GitHub/LineageOS/android_kernel_motorola_exynos9610.git
6 years agonet: aquantia: Fix IFF_ALLMULTI flag functionality
Dmitry Bogdanov [Wed, 8 Aug 2018 11:06:32 +0000 (14:06 +0300)]
net: aquantia: Fix IFF_ALLMULTI flag functionality

[ Upstream commit 11ba961c916127651e12af6cad3891f8aeb25aa9 ]

It was noticed that NIC always pass all multicast traffic to the host
regardless of IFF_ALLMULTI flag on the interface.
The rule in MC Filter Table in NIC, that is configured to accept any
multicast packets, is turning on if IFF_MULTICAST flag is set on the
interface. It leads to passing all multicast traffic to the host.
This fix changes the condition to turn on that rule by checking
IFF_ALLMULTI flag as it should.

Fixes: b21f502f84be ("net:ethernet:aquantia: Fix for multicast filter handling.")
Signed-off-by: Dmitry Bogdanov <dmitry.bogdanov@aquantia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoip6_tunnel: use the right value for ipv4 min mtu check in ip6_tnl_xmit
Xin Long [Sun, 5 Aug 2018 14:46:07 +0000 (22:46 +0800)]
ip6_tunnel: use the right value for ipv4 min mtu check in ip6_tnl_xmit

[ Upstream commit 82a40777de12728dedf4075453b694f0d1baee80 ]

According to RFC791, 68 bytes is the minimum size of IPv4 datagram every
device must be able to forward without further fragmentation while 576
bytes is the minimum size of IPv4 datagram every device has to be able
to receive, so in ip6_tnl_xmit(), 68(IPV4_MIN_MTU) should be the right
value for the ipv4 min mtu check in ip6_tnl_xmit.

While at it, change to use max() instead of if statement.

Fixes: c9fefa08190f ("ip6_tunnel: get the min mtu properly in ip6_tnl_xmit")
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agovhost: reset metadata cache when initializing new IOTLB
Jason Wang [Wed, 8 Aug 2018 03:43:04 +0000 (11:43 +0800)]
vhost: reset metadata cache when initializing new IOTLB

[ Upstream commit b13f9c6364373a1b9f71e9846dc4fb199296f926 ]

We need to reset metadata cache during new IOTLB initialization,
otherwise the stale pointers to previous IOTLB may be still accessed
which will lead a use after free.

Reported-by: syzbot+c51e6736a1bf614b3272@syzkaller.appspotmail.com
Fixes: f88949138058 ("vhost: introduce O(1) vq metadata cache")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agonet_sched: Fix missing res info when create new tc_index filter
Hangbin Liu [Mon, 13 Aug 2018 10:44:04 +0000 (18:44 +0800)]
net_sched: Fix missing res info when create new tc_index filter

[ Upstream commit 008369dcc5f7bfba526c98054f8525322acf0ea3 ]

Li Shuang reported the following warn:

[  733.484610] WARNING: CPU: 6 PID: 21123 at net/sched/sch_cbq.c:1418 cbq_destroy_class+0x5d/0x70 [sch_cbq]
[  733.495190] Modules linked in: sch_cbq cls_tcindex sch_dsmark rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache xt_CHECKSUM iptable_mangle ipt_MASQUERADE iptable_nat l
[  733.574155]  syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm igb ixgbe ahci libahci i2c_algo_bit libata i40e i2c_core dca mdio megaraid_sas dm_mirror dm_region_hash dm_log dm_mod
[  733.592500] CPU: 6 PID: 21123 Comm: tc Not tainted 4.18.0-rc8.latest+ #131
[  733.600169] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.1.5 04/11/2016
[  733.608518] RIP: 0010:cbq_destroy_class+0x5d/0x70 [sch_cbq]
[  733.614734] Code: e7 d9 d2 48 8b 7b 48 e8 61 05 da d2 48 8d bb f8 00 00 00 e8 75 ae d5 d2 48 39 eb 74 0a 48 89 df 5b 5d e9 16 6c 94 d2 5b 5d c3 <0f> 0b eb b6 0f 1f 44 00 00 66 2e 0f 1f 84
[  733.635798] RSP: 0018:ffffbfbb066bb9d8 EFLAGS: 00010202
[  733.641627] RAX: 0000000000000001 RBX: ffff9cdd17392800 RCX: 000000008010000f
[  733.649588] RDX: ffff9cdd1df547e0 RSI: ffff9cdd17392800 RDI: ffff9cdd0f84c800
[  733.657547] RBP: ffff9cdd0f84c800 R08: 0000000000000001 R09: 0000000000000000
[  733.665508] R10: ffff9cdd0f84d000 R11: 0000000000000001 R12: 0000000000000001
[  733.673469] R13: 0000000000000000 R14: 0000000000000001 R15: ffff9cdd17392200
[  733.681430] FS:  00007f911890a740(0000) GS:ffff9cdd1f8c0000(0000) knlGS:0000000000000000
[  733.690456] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  733.696864] CR2: 0000000000b5544c CR3: 0000000859374002 CR4: 00000000001606e0
[  733.704826] Call Trace:
[  733.707554]  cbq_destroy+0xa1/0xd0 [sch_cbq]
[  733.712318]  qdisc_destroy+0x62/0x130
[  733.716401]  dsmark_destroy+0x2a/0x70 [sch_dsmark]
[  733.721745]  qdisc_destroy+0x62/0x130
[  733.725829]  qdisc_graft+0x3ba/0x470
[  733.729817]  tc_get_qdisc+0x2a6/0x2c0
[  733.733901]  ? cred_has_capability+0x7d/0x130
[  733.738761]  rtnetlink_rcv_msg+0x263/0x2d0
[  733.743330]  ? rtnl_calcit.isra.30+0x110/0x110
[  733.748287]  netlink_rcv_skb+0x4d/0x130
[  733.752576]  netlink_unicast+0x1a3/0x250
[  733.756949]  netlink_sendmsg+0x2ae/0x3a0
[  733.761324]  sock_sendmsg+0x36/0x40
[  733.765213]  ___sys_sendmsg+0x26f/0x2d0
[  733.769493]  ? handle_pte_fault+0x586/0xdf0
[  733.774158]  ? __handle_mm_fault+0x389/0x500
[  733.778919]  ? __sys_sendmsg+0x5e/0xa0
[  733.783099]  __sys_sendmsg+0x5e/0xa0
[  733.787087]  do_syscall_64+0x5b/0x180
[  733.791171]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  733.796805] RIP: 0033:0x7f9117f23f10
[  733.800791] Code: c3 48 8b 05 82 6f 2c 00 f7 db 64 89 18 48 83 cb ff eb dd 0f 1f 80 00 00 00 00 83 3d 8d d0 2c 00 00 75 10 b8 2e 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8
[  733.821873] RSP: 002b:00007ffe96818398 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  733.830319] RAX: ffffffffffffffda RBX: 000000005b71244c RCX: 00007f9117f23f10
[  733.838280] RDX: 0000000000000000 RSI: 00007ffe968183e0 RDI: 0000000000000003
[  733.846241] RBP: 00007ffe968183e0 R08: 000000000000ffff R09: 0000000000000003
[  733.854202] R10: 00007ffe96817e20 R11: 0000000000000246 R12: 0000000000000000
[  733.862161] R13: 0000000000662ee0 R14: 0000000000000000 R15: 0000000000000000
[  733.870121] ---[ end trace 28edd4aad712ddca ]---

This is because we didn't update f->result.res when create new filter. Then in
tcindex_delete() -> tcf_unbind_filter(), we will failed to find out the res
and unbind filter, which will trigger the WARN_ON() in cbq_destroy_class().

Fix it by updating f->result.res when create new filter.

Fixes: 6e0565697a106 ("net_sched: fix another crash in cls_tcindex")
Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agovsock: split dwork to avoid reinitializations
Cong Wang [Mon, 6 Aug 2018 18:06:02 +0000 (11:06 -0700)]
vsock: split dwork to avoid reinitializations

[ Upstream commit 455f05ecd2b219e9a216050796d30c830d9bc393 ]

syzbot reported that we reinitialize an active delayed
work in vsock_stream_connect():

ODEBUG: init active (active state 0) object type: timer_list hint:
delayed_work_timer_fn+0x0/0x90 kernel/workqueue.c:1414
WARNING: CPU: 1 PID: 11518 at lib/debugobjects.c:329
debug_print_object+0x16a/0x210 lib/debugobjects.c:326

The pattern is apparently wrong, we should only initialize
the dealyed work once and could repeatly schedule it. So we
have to move out the initializations to allocation side.
And to avoid confusion, we can split the shared dwork
into two, instead of re-using the same one.

Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Reported-by: <syzbot+8a9b1bd330476a4f3db6@syzkaller.appspotmail.com>
Cc: Andy king <acking@vmware.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agonet_sched: fix NULL pointer dereference when delete tcindex filter
Hangbin Liu [Mon, 13 Aug 2018 10:44:03 +0000 (18:44 +0800)]
net_sched: fix NULL pointer dereference when delete tcindex filter

[ Upstream commit 2df8bee5654bb2b7312662ca6810d4dc16b0b67f ]

Li Shuang reported the following crash:

[   71.267724] BUG: unable to handle kernel NULL pointer dereference at 0000000000000004
[   71.276456] PGD 800000085d9bd067 P4D 800000085d9bd067 PUD 859a0b067 PMD 0
[   71.284127] Oops: 0000 [#1] SMP PTI
[   71.288015] CPU: 12 PID: 2386 Comm: tc Not tainted 4.18.0-rc8.latest+ #131
[   71.295686] Hardware name: Dell Inc. PowerEdge R730/0WCJNT, BIOS 2.1.5 04/11/2016
[   71.304037] RIP: 0010:tcindex_delete+0x72/0x280 [cls_tcindex]
[   71.310446] Code: 00 31 f6 48 87 75 20 48 85 f6 74 11 48 8b 47 18 48 8b 40 08 48 8b 40 50 e8 fb a6 f8 fc 48 85 db 0f 84 dc 00 00 00 48 8b 73 18 <8b> 56 04 48 8d 7e 04 85 d2 0f 84 7b 01 00
[   71.331517] RSP: 0018:ffffb45207b3f898 EFLAGS: 00010282
[   71.337345] RAX: ffff8ad3d72d6360 RBX: ffff8acc84393680 RCX: 000000000000002e
[   71.345306] RDX: ffff8ad3d72c8570 RSI: 0000000000000000 RDI: ffff8ad847a45800
[   71.353277] RBP: ffff8acc84393688 R08: ffff8ad3d72c8400 R09: 0000000000000000
[   71.361238] R10: ffff8ad3de786e00 R11: 0000000000000000 R12: ffffb45207b3f8c7
[   71.369199] R13: ffff8ad3d93bd2a0 R14: 000000000000002e R15: ffff8ad3d72c9600
[   71.377161] FS:  00007f9d3ec3e740(0000) GS:ffff8ad3df980000(0000) knlGS:0000000000000000
[   71.386188] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   71.392597] CR2: 0000000000000004 CR3: 0000000852f06003 CR4: 00000000001606e0
[   71.400558] Call Trace:
[   71.403299]  tcindex_destroy_element+0x25/0x40 [cls_tcindex]
[   71.409611]  tcindex_walk+0xbb/0x110 [cls_tcindex]
[   71.414953]  tcindex_destroy+0x44/0x90 [cls_tcindex]
[   71.420492]  ? tcindex_delete+0x280/0x280 [cls_tcindex]
[   71.426323]  tcf_proto_destroy+0x16/0x40
[   71.430696]  tcf_chain_flush+0x51/0x70
[   71.434876]  tcf_block_put_ext.part.30+0x8f/0x1b0
[   71.440122]  tcf_block_put+0x4d/0x70
[   71.444108]  cbq_destroy+0x4d/0xd0 [sch_cbq]
[   71.448869]  qdisc_destroy+0x62/0x130
[   71.452951]  dsmark_destroy+0x2a/0x70 [sch_dsmark]
[   71.458300]  qdisc_destroy+0x62/0x130
[   71.462373]  qdisc_graft+0x3ba/0x470
[   71.466359]  tc_get_qdisc+0x2a6/0x2c0
[   71.470443]  ? cred_has_capability+0x7d/0x130
[   71.475307]  rtnetlink_rcv_msg+0x263/0x2d0
[   71.479875]  ? rtnl_calcit.isra.30+0x110/0x110
[   71.484832]  netlink_rcv_skb+0x4d/0x130
[   71.489109]  netlink_unicast+0x1a3/0x250
[   71.493482]  netlink_sendmsg+0x2ae/0x3a0
[   71.497859]  sock_sendmsg+0x36/0x40
[   71.501748]  ___sys_sendmsg+0x26f/0x2d0
[   71.506029]  ? handle_pte_fault+0x586/0xdf0
[   71.510694]  ? __handle_mm_fault+0x389/0x500
[   71.515457]  ? __sys_sendmsg+0x5e/0xa0
[   71.519636]  __sys_sendmsg+0x5e/0xa0
[   71.523626]  do_syscall_64+0x5b/0x180
[   71.527711]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   71.533345] RIP: 0033:0x7f9d3e257f10
[   71.537331] Code: c3 48 8b 05 82 6f 2c 00 f7 db 64 89 18 48 83 cb ff eb dd 0f 1f 80 00 00 00 00 83 3d 8d d0 2c 00 00 75 10 b8 2e 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8
[   71.558401] RSP: 002b:00007fff6f893398 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[   71.566848] RAX: ffffffffffffffda RBX: 000000005b71274d RCX: 00007f9d3e257f10
[   71.574810] RDX: 0000000000000000 RSI: 00007fff6f8933e0 RDI: 0000000000000003
[   71.582770] RBP: 00007fff6f8933e0 R08: 000000000000ffff R09: 0000000000000003
[   71.590729] R10: 00007fff6f892e20 R11: 0000000000000246 R12: 0000000000000000
[   71.598689] R13: 0000000000662ee0 R14: 0000000000000000 R15: 0000000000000000
[   71.606651] Modules linked in: sch_cbq cls_tcindex sch_dsmark xt_CHECKSUM iptable_mangle ipt_MASQUERADE iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_coni
[   71.685425]  libahci i2c_algo_bit i2c_core i40e libata dca mdio megaraid_sas dm_mirror dm_region_hash dm_log dm_mod
[   71.697075] CR2: 0000000000000004
[   71.700792] ---[ end trace f604eb1acacd978b ]---

Reproducer:
tc qdisc add dev lo handle 1:0 root dsmark indices 64 set_tc_index
tc filter add dev lo parent 1:0 protocol ip prio 1 tcindex mask 0xfc shift 2
tc qdisc add dev lo parent 1:0 handle 2:0 cbq bandwidth 10Mbit cell 8 avpkt 1000 mpu 64
tc class add dev lo parent 2:0 classid 2:1 cbq bandwidth 10Mbit rate 1500Kbit avpkt 1000 prio 1 bounded isolated allot 1514 weight 1 maxburst 10
tc filter add dev lo parent 2:0 protocol ip prio 1 handle 0x2e tcindex classid 2:1 pass_on
tc qdisc add dev lo parent 2:1 pfifo limit 5
tc qdisc del dev lo root

This is because in tcindex_set_parms, when there is no old_r, we set new
exts to cr.exts. And we didn't set it to filter when r == &new_filter_result.

Then in tcindex_delete() -> tcf_exts_get_net(), we will get NULL pointer
dereference as we didn't init exts.

Fix it by moving tcf_exts_change() after "if (old_r && old_r != r)" check.
Then we don't need "cr" as there is no errout after that.

Fixes: bf63ac73b3e13 ("net_sched: fix an oops in tcindex filter")
Reported-by: Li Shuang <shuali@redhat.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agollc: use refcount_inc_not_zero() for llc_sap_find()
Cong Wang [Tue, 7 Aug 2018 19:41:38 +0000 (12:41 -0700)]
llc: use refcount_inc_not_zero() for llc_sap_find()

[ Upstream commit 0dcb82254d65f72333aa50ad626d1e9665ad093b ]

llc_sap_put() decreases the refcnt before deleting sap
from the global list. Therefore, there is a chance
llc_sap_find() could find a sap with zero refcnt
in this global list.

Close this race condition by checking if refcnt is zero
or not in llc_sap_find(), if it is zero then it is being
removed so we can just treat it as gone.

Reported-by: <syzbot+278893f3f7803871f7ce@syzkaller.appspotmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agol2tp: use sk_dst_check() to avoid race on sk->sk_dst_cache
Wei Wang [Fri, 10 Aug 2018 18:14:56 +0000 (11:14 -0700)]
l2tp: use sk_dst_check() to avoid race on sk->sk_dst_cache

[ Upstream commit 6d37fa49da1e8db8fb1995be22ac837ca41ac8a8 ]

In l2tp code, if it is a L2TP_UDP_ENCAP tunnel, tunnel->sk points to a
UDP socket. User could call sendmsg() on both this tunnel and the UDP
socket itself concurrently. As l2tp_xmit_skb() holds socket lock and call
__sk_dst_check() to refresh sk->sk_dst_cache, while udpv6_sendmsg() is
lockless and call sk_dst_check() to refresh sk->sk_dst_cache, there
could be a race and cause the dst cache to be freed multiple times.
So we fix l2tp side code to always call sk_dst_check() to garantee
xchg() is called when refreshing sk->sk_dst_cache to avoid race
conditions.

Syzkaller reported stack trace:
BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: use-after-free in atomic_fetch_add_unless include/linux/atomic.h:575 [inline]
BUG: KASAN: use-after-free in atomic_add_unless include/linux/atomic.h:597 [inline]
BUG: KASAN: use-after-free in dst_hold_safe include/net/dst.h:308 [inline]
BUG: KASAN: use-after-free in ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029
Read of size 4 at addr ffff8801aea9a880 by task syz-executor129/4829

CPU: 0 PID: 4829 Comm: syz-executor129 Not tainted 4.18.0-rc7-next-20180802+ #30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 atomic_fetch_add_unless include/linux/atomic.h:575 [inline]
 atomic_add_unless include/linux/atomic.h:597 [inline]
 dst_hold_safe include/net/dst.h:308 [inline]
 ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029
 rt6_get_pcpu_route net/ipv6/route.c:1249 [inline]
 ip6_pol_route+0x354/0xd20 net/ipv6/route.c:1922
 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2098
 fib6_rule_lookup+0x283/0x890 net/ipv6/fib6_rules.c:122
 ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:2126
 ip6_dst_lookup_tail+0x1278/0x1da0 net/ipv6/ip6_output.c:978
 ip6_dst_lookup_flow+0xc8/0x270 net/ipv6/ip6_output.c:1079
 ip6_sk_dst_lookup_flow+0x5ed/0xc50 net/ipv6/ip6_output.c:1117
 udpv6_sendmsg+0x2163/0x36b0 net/ipv6/udp.c:1354
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:632
 ___sys_sendmsg+0x51d/0x930 net/socket.c:2115
 __sys_sendmmsg+0x240/0x6f0 net/socket.c:2210
 __do_sys_sendmmsg net/socket.c:2239 [inline]
 __se_sys_sendmmsg net/socket.c:2236 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2236
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446a29
Code: e8 ac b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4de5532db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 0000000000446a29
RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003
RBP: 00000000006dcc30 R08: 00007f4de5533700 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c
R13: 00007ffe2b830fdf R14: 00007f4de55339c0 R15: 0000000000000001

Fixes: 71b1391a4128 ("l2tp: ensure sk->dst is still valid")
Reported-by: syzbot+05f840f3b04f211bad55@syzkaller.appspotmail.com
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Cc: Guillaume Nault <g.nault@alphalink.fr>
Cc: David Ahern <dsahern@gmail.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agodccp: fix undefined behavior with 'cwnd' shift in ccid2_cwnd_restart()
Alexey Kodanev [Tue, 7 Aug 2018 17:03:57 +0000 (20:03 +0300)]
dccp: fix undefined behavior with 'cwnd' shift in ccid2_cwnd_restart()

[ Upstream commit 61ef4b07fcdc30535889990cf4229766502561cf ]

The shift of 'cwnd' with '(now - hc->tx_lsndtime) / hc->tx_rto' value
can lead to undefined behavior [1].

In order to fix this use a gradual shift of the window with a 'while'
loop, similar to what tcp_cwnd_restart() is doing.

When comparing delta and RTO there is a minor difference between TCP
and DCCP, the last one also invokes dccp_cwnd_restart() and reduces
'cwnd' if delta equals RTO. That case is preserved in this change.

[1]:
[40850.963623] UBSAN: Undefined behaviour in net/dccp/ccids/ccid2.c:237:7
[40851.043858] shift exponent 67 is too large for 32-bit type 'unsigned int'
[40851.127163] CPU: 3 PID: 15940 Comm: netstress Tainted: G        W   E     4.18.0-rc7.x86_64 #1
...
[40851.377176] Call Trace:
[40851.408503]  dump_stack+0xf1/0x17b
[40851.451331]  ? show_regs_print_info+0x5/0x5
[40851.503555]  ubsan_epilogue+0x9/0x7c
[40851.548363]  __ubsan_handle_shift_out_of_bounds+0x25b/0x2b4
[40851.617109]  ? __ubsan_handle_load_invalid_value+0x18f/0x18f
[40851.686796]  ? xfrm4_output_finish+0x80/0x80
[40851.739827]  ? lock_downgrade+0x6d0/0x6d0
[40851.789744]  ? xfrm4_prepare_output+0x160/0x160
[40851.845912]  ? ip_queue_xmit+0x810/0x1db0
[40851.895845]  ? ccid2_hc_tx_packet_sent+0xd36/0x10a0 [dccp]
[40851.963530]  ccid2_hc_tx_packet_sent+0xd36/0x10a0 [dccp]
[40852.029063]  dccp_xmit_packet+0x1d3/0x720 [dccp]
[40852.086254]  dccp_write_xmit+0x116/0x1d0 [dccp]
[40852.142412]  dccp_sendmsg+0x428/0xb20 [dccp]
[40852.195454]  ? inet_dccp_listen+0x200/0x200 [dccp]
[40852.254833]  ? sched_clock+0x5/0x10
[40852.298508]  ? sched_clock+0x5/0x10
[40852.342194]  ? inet_create+0xdf0/0xdf0
[40852.388988]  sock_sendmsg+0xd9/0x160
...

Fixes: 113ced1f52e5 ("dccp ccid-2: Perform congestion-window validation")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoLinux 4.14.65
Greg Kroah-Hartman [Sat, 18 Aug 2018 08:48:00 +0000 (10:48 +0200)]
Linux 4.14.65

6 years agox86/speculation/l1tf: Exempt zeroed PTEs from inversion
Sean Christopherson [Fri, 17 Aug 2018 17:27:36 +0000 (10:27 -0700)]
x86/speculation/l1tf: Exempt zeroed PTEs from inversion

commit f19f5c49bbc3ffcc9126cc245fc1b24cc29f4a37 upstream.

It turns out that we should *not* invert all not-present mappings,
because the all zeroes case is obviously special.

clear_page() does not undergo the XOR logic to invert the address bits,
i.e. PTE, PMD and PUD entries that have not been individually written
will have val=0 and so will trigger __pte_needs_invert(). As a result,
{pte,pmd,pud}_pfn() will return the wrong PFN value, i.e. all ones
(adjusted by the max PFN mask) instead of zero. A zeroed entry is ok
because the page at physical address 0 is reserved early in boot
specifically to mitigate L1TF, so explicitly exempt them from the
inversion when reading the PFN.

Manifested as an unexpected mprotect(..., PROT_NONE) failure when called
on a VMA that has VM_PFNMAP and was mmap'd to as something other than
PROT_NONE but never used. mprotect() sends the PROT_NONE request down
prot_none_walk(), which walks the PTEs to check the PFNs.
prot_none_pte_entry() gets the bogus PFN from pte_pfn() and returns
-EACCES because it thinks mprotect() is trying to adjust a high MMIO
address.

[ This is a very modified version of Sean's original patch, but all
  credit goes to Sean for doing this and also pointing out that
  sometimes the __pte_needs_invert() function only gets the protection
  bits, not the full eventual pte.  But zero remains special even in
  just protection bits, so that's ok.   - Linus ]

Fixes: f22cc87f6c1f ("x86/speculation/l1tf: Invert all not present mappings")
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoLinux 4.14.64
Greg Kroah-Hartman [Fri, 17 Aug 2018 19:01:12 +0000 (21:01 +0200)]
Linux 4.14.64

6 years agox86/mm: Add TLB purge to free pmd/pte page interfaces
Toshi Kani [Wed, 27 Jun 2018 14:13:48 +0000 (08:13 -0600)]
x86/mm: Add TLB purge to free pmd/pte page interfaces

commit 5e0fb5df2ee871b841f96f9cb6a7f2784e96aa4e upstream.

ioremap() calls pud_free_pmd_page() / pmd_free_pte_page() when it creates
a pud / pmd map.  The following preconditions are met at their entry.
 - All pte entries for a target pud/pmd address range have been cleared.
 - System-wide TLB purges have been peformed for a target pud/pmd address
   range.

The preconditions assure that there is no stale TLB entry for the range.
Speculation may not cache TLB entries since it requires all levels of page
entries, including ptes, to have P & A-bits set for an associated address.
However, speculation may cache pud/pmd entries (paging-structure caches)
when they have P-bit set.

Add a system-wide TLB purge (INVLPG) to a single page after clearing
pud/pmd entry's P-bit.

SDM 4.10.4.1, Operation that Invalidate TLBs and Paging-Structure Caches,
states that:
  INVLPG invalidates all paging-structure caches associated with the
  current PCID regardless of the liner addresses to which they correspond.

Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: mhocko@suse.com
Cc: akpm@linux-foundation.org
Cc: hpa@zytor.com
Cc: cpandya@codeaurora.org
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Joerg Roedel <joro@8bytes.org>
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20180627141348.21777-4-toshi.kani@hpe.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoioremap: Update pgtable free interfaces with addr
Chintan Pandya [Wed, 27 Jun 2018 14:13:47 +0000 (08:13 -0600)]
ioremap: Update pgtable free interfaces with addr

commit 785a19f9d1dd8a4ab2d0633be4656653bd3de1fc upstream.

The following kernel panic was observed on ARM64 platform due to a stale
TLB entry.

 1. ioremap with 4K size, a valid pte page table is set.
 2. iounmap it, its pte entry is set to 0.
 3. ioremap the same address with 2M size, update its pmd entry with
    a new value.
 4. CPU may hit an exception because the old pmd entry is still in TLB,
    which leads to a kernel panic.

Commit b6bdb7517c3d ("mm/vmalloc: add interfaces to free unmapped page
table") has addressed this panic by falling to pte mappings in the above
case on ARM64.

To support pmd mappings in all cases, TLB purge needs to be performed
in this case on ARM64.

Add a new arg, 'addr', to pud_free_pmd_page() and pmd_free_pte_page()
so that TLB purge can be added later in seprate patches.

[toshi.kani@hpe.com: merge changes, rewrite patch description]
Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
Signed-off-by: Chintan Pandya <cpandya@codeaurora.org>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: mhocko@suse.com
Cc: akpm@linux-foundation.org
Cc: hpa@zytor.com
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: Will Deacon <will.deacon@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20180627141348.21777-3-toshi.kani@hpe.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoBluetooth: hidp: buffer overflow in hidp_process_report
Mark Salyzyn [Tue, 31 Jul 2018 22:02:13 +0000 (15:02 -0700)]
Bluetooth: hidp: buffer overflow in hidp_process_report

commit 7992c18810e568b95c869b227137a2215702a805 upstream.

CVE-2018-9363

The buffer length is unsigned at all layers, but gets cast to int and
checked in hidp_process_report and can lead to a buffer overflow.
Switch len parameter to unsigned int to resolve issue.

This affects 3.18 and newer kernels.

Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Fixes: a4b1b5877b514b276f0f31efe02388a9c2836728 ("HID: Bluetooth: hidp: make sure input buffers are big enough")
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: linux-bluetooth@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: security@kernel.org
Cc: kernel-team@android.com
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoASoC: Intel: cht_bsw_max98090_ti: Fix jack initialization
Thierry Escande [Fri, 8 Sep 2017 05:13:08 +0000 (00:13 -0500)]
ASoC: Intel: cht_bsw_max98090_ti: Fix jack initialization

commit 3bbda5a38601f7675a214be2044e41d7749e6c7b upstream.

If the ts3a227e audio accessory detection hardware is present and its
driver probed, the jack needs to be created before enabling jack
detection in the ts3a227e driver. With this patch, the jack is
instantiated in the max98090 headset init function if the ts3a227e is
present. This fixes a null pointer dereference as the jack detection
enabling function in the ts3a driver was called before the jack is
created.

[minor correction to keep error handling on jack creation the same
as before by Pierre Bossart]

Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-By: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoASoC: msm8916-wcd-digital: fix RX2 MIX1 and RX3 MIX1
Jean-François Têtu [Fri, 22 Sep 2017 21:44:28 +0000 (17:44 -0400)]
ASoC: msm8916-wcd-digital: fix RX2 MIX1 and RX3 MIX1

commit f53ee247ad546183fc13739adafc5579b9f0ebc0 upstream.

The kcontrol for the third input (rxN_mix1_inp3) of both RX2
and RX3 mixers are not using the correct control register. This simple
patch fixes this.

Signed-off-by: Jean-François Têtu <jean-francois.tetu@savoirfairelinux.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoblock, bfq: fix wrong init of saved start time for weight raising
Paolo Valente [Thu, 21 Sep 2017 09:04:00 +0000 (11:04 +0200)]
block, bfq: fix wrong init of saved start time for weight raising

commit 4baa8bb13f41307f3eb62fe91f93a1a798ebef53 upstream.

This commit fixes a bug that causes bfq to fail to guarantee a high
responsiveness on some drives, if there is heavy random read+write I/O
in the background. More precisely, such a failure allowed this bug to
be found [1], but the bug may well cause other yet unreported
anomalies.

BFQ raises the weight of the bfq_queues associated with soft real-time
applications, to privilege the I/O, and thus reduce latency, for these
applications. This mechanism is named soft-real-time weight raising in
BFQ. A soft real-time period may happen to be nested into an
interactive weight raising period, i.e., it may happen that, when a
bfq_queue switches to a soft real-time weight-raised state, the
bfq_queue is already being weight-raised because deemed interactive
too. In this case, BFQ saves in a special variable
wr_start_at_switch_to_srt, the time instant when the interactive
weight-raising period started for the bfq_queue, i.e., the time
instant when BFQ started to deem the bfq_queue interactive. This value
is then used to check whether the interactive weight-raising period
would still be in progress when the soft real-time weight-raising
period ends.  If so, interactive weight raising is restored for the
bfq_queue. This restore is useful, in particular, because it prevents
bfq_queues from losing their interactive weight raising prematurely,
as a consequence of spurious, short-lived soft real-time
weight-raising periods caused by wrong detections as soft real-time.

If, instead, a bfq_queue switches to soft-real-time weight raising
while it *is not* already in an interactive weight-raising period,
then the variable wr_start_at_switch_to_srt has no meaning during the
following soft real-time weight-raising period. Unfortunately the
handling of this case is wrong in BFQ: not only the variable is not
flagged somehow as meaningless, but it is also set to the time when
the switch to soft real-time weight-raising occurs. This may cause an
interactive weight-raising period to be considered mistakenly as still
in progress, and thus a spurious interactive weight-raising period to
start for the bfq_queue, at the end of the soft-real-time
weight-raising period. In particular the spurious interactive
weight-raising period will be considered as still in progress, if the
soft-real-time weight-raising period does not last very long. The
bfq_queue will then be wrongly privileged and, if I/O bound, will
unjustly steal bandwidth to truly interactive or soft real-time
bfq_queues, harming responsiveness and low latency.

This commit fixes this issue by just setting wr_start_at_switch_to_srt
to minus infinity (farthest past time instant according to jiffies
macros): when the soft-real-time weight-raising period ends, certainly
no interactive weight-raising period will be considered as still in
progress.

[1] Background I/O Type: Random - Background I/O mix: Reads and writes
- Application to start: LibreOffice Writer in
http://www.phoronix.com/scan.php?page=news_item&px=Linux-4.13-IO-Laptop

Signed-off-by: Paolo Valente <paolo.valente@linaro.org>
Signed-off-by: Angelo Ruocco <angeloruocco90@gmail.com>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Lee Tibbert <lee.tibbert@gmail.com>
Tested-by: Mirko Montanari <mirkomontanari91@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoclk: sunxi-ng: Fix missing CLK_SET_RATE_PARENT in ccu-sun4i-a10.c
Alexander Syring [Thu, 14 Sep 2017 12:05:19 +0000 (14:05 +0200)]
clk: sunxi-ng: Fix missing CLK_SET_RATE_PARENT in ccu-sun4i-a10.c

commit a894990ac994a53bc5a0cc694eb12f3c064c18c5 upstream.

When using cpufreq-dt with default govenor other than "performance"
system freezes while booting.
Adding CLK_SET_RATE_PARENT | CLK_IS_CRITICAL to clk_cpu fixes the
problem.

Tested on Cubietruck (A20).

Fixes: c84f5683f6E ("clk: sunxi-ng: Add sun4i/sun7i CCU driver")
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Alexander Syring <alex@asyring.de>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoASoC: rsnd: fix ADG flags
Kuninori Morimoto [Mon, 11 Sep 2017 04:17:26 +0000 (04:17 +0000)]
ASoC: rsnd: fix ADG flags

commit b7165d26bf730567ab081bb9383aff82cd43d9ea upstream.

Current ADG driver is over-writing flags. This patch fixes it.

Reported-by: Hiroyuki Yokoyama <hiroyuki.yokoyama.vx@renesas.com>
Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agofw_cfg: fix driver remove
Marc-André Lureau [Mon, 20 Nov 2017 09:55:15 +0000 (10:55 +0100)]
fw_cfg: fix driver remove

commit 23f1b8d938c861ee0bbb786162f7ce0685f722ec upstream.

On driver remove(), all objects created during probe() should be
removed, but sysfs qemu_fw_cfg/rev file was left. Also reorder
functions to match probe() error cleanup code.

Cc: stable@vger.kernel.org
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agosched/debug: Fix task state recording/printout
Thomas Gleixner [Wed, 22 Nov 2017 12:05:48 +0000 (13:05 +0100)]
sched/debug: Fix task state recording/printout

commit 3f5fe9fef5b2da06b6319fab8123056da5217c3f upstream.

The recent conversion of the task state recording to use task_state_index()
broke the sched_switch tracepoint task state output.

task_state_index() returns surprisingly an index (0-7) which is then
printed with __print_flags() applying bitmasks. Not really working and
resulting in weird states like 'prev_state=t' instead of 'prev_state=I'.

Use TASK_REPORT_MAX instead of TASK_STATE_MAX to report preemption. Build a
bitmask from the return value of task_state_index() and store it in
entry->prev_state, which makes __print_flags() work as expected.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: stable@vger.kernel.org
Fixes: efb40f588b43 ("sched/tracing: Fix trace_sched_switch task-state printing")
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1711221304180.1751@nanos
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoACPI / APEI: Remove ghes_ioremap_area
James Morse [Mon, 6 Nov 2017 18:44:25 +0000 (18:44 +0000)]
ACPI / APEI: Remove ghes_ioremap_area

commit 520e18a5080d2c444a03280d99c8a35cb667d321 upstream.

Now that nothing is using the ghes_ioremap_area pages, rip them out.

Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Tested-by: Tyler Baicar <tbaicar@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocrypto: skcipher - fix crash flushing dcache in error path
Eric Biggers [Mon, 23 Jul 2018 17:54:56 +0000 (10:54 -0700)]
crypto: skcipher - fix crash flushing dcache in error path

commit 8088d3dd4d7c6933a65aa169393b5d88d8065672 upstream.

scatterwalk_done() is only meant to be called after a nonzero number of
bytes have been processed, since scatterwalk_pagedone() will flush the
dcache of the *previous* page.  But in the error case of
skcipher_walk_done(), e.g. if the input wasn't an integer number of
blocks, scatterwalk_done() was actually called after advancing 0 bytes.
This caused a crash ("BUG: unable to handle kernel paging request")
during '!PageSlab(page)' on architectures like arm and arm64 that define
ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE, provided that the input was
page-aligned as in that case walk->offset == 0.

Fix it by reorganizing skcipher_walk_done() to skip the
scatterwalk_advance() and scatterwalk_done() if an error has occurred.

This bug was found by syzkaller fuzzing.

Reproducer, assuming ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE:

#include <linux/if_alg.h>
#include <sys/socket.h>
#include <unistd.h>

int main()
{
struct sockaddr_alg addr = {
.salg_type = "skcipher",
.salg_name = "cbc(aes-generic)",
};
char buffer[4096] __attribute__((aligned(4096))) = { 0 };
int fd;

fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
bind(fd, (void *)&addr, sizeof(addr));
setsockopt(fd, SOL_ALG, ALG_SET_KEY, buffer, 16);
fd = accept(fd, NULL, NULL);
write(fd, buffer, 15);
read(fd, buffer, 15);
}

Reported-by: Liu Chao <liuchao741@huawei.com>
Fixes: b286d8b1a690 ("crypto: skcipher - Add skcipher walk interface")
Cc: <stable@vger.kernel.org> # v4.10+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocrypto: skcipher - fix aligning block size in skcipher_copy_iv()
Eric Biggers [Mon, 23 Jul 2018 16:57:50 +0000 (09:57 -0700)]
crypto: skcipher - fix aligning block size in skcipher_copy_iv()

commit 0567fc9e90b9b1c8dbce8a5468758e6206744d4a upstream.

The ALIGN() macro needs to be passed the alignment, not the alignmask
(which is the alignment minus 1).

Fixes: b286d8b1a690 ("crypto: skcipher - Add skcipher walk interface")
Cc: <stable@vger.kernel.org> # v4.10+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocrypto: ablkcipher - fix crash flushing dcache in error path
Eric Biggers [Mon, 23 Jul 2018 17:54:58 +0000 (10:54 -0700)]
crypto: ablkcipher - fix crash flushing dcache in error path

commit 318abdfbe708aaaa652c79fb500e9bd60521f9dc upstream.

Like the skcipher_walk and blkcipher_walk cases:

scatterwalk_done() is only meant to be called after a nonzero number of
bytes have been processed, since scatterwalk_pagedone() will flush the
dcache of the *previous* page.  But in the error case of
ablkcipher_walk_done(), e.g. if the input wasn't an integer number of
blocks, scatterwalk_done() was actually called after advancing 0 bytes.
This caused a crash ("BUG: unable to handle kernel paging request")
during '!PageSlab(page)' on architectures like arm and arm64 that define
ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE, provided that the input was
page-aligned as in that case walk->offset == 0.

Fix it by reorganizing ablkcipher_walk_done() to skip the
scatterwalk_advance() and scatterwalk_done() if an error has occurred.

Reported-by: Liu Chao <liuchao741@huawei.com>
Fixes: bf06099db18a ("crypto: skcipher - Add ablkcipher_walk interfaces")
Cc: <stable@vger.kernel.org> # v2.6.35+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocrypto: blkcipher - fix crash flushing dcache in error path
Eric Biggers [Mon, 23 Jul 2018 17:54:57 +0000 (10:54 -0700)]
crypto: blkcipher - fix crash flushing dcache in error path

commit 0868def3e4100591e7a1fdbf3eed1439cc8f7ca3 upstream.

Like the skcipher_walk case:

scatterwalk_done() is only meant to be called after a nonzero number of
bytes have been processed, since scatterwalk_pagedone() will flush the
dcache of the *previous* page.  But in the error case of
blkcipher_walk_done(), e.g. if the input wasn't an integer number of
blocks, scatterwalk_done() was actually called after advancing 0 bytes.
This caused a crash ("BUG: unable to handle kernel paging request")
during '!PageSlab(page)' on architectures like arm and arm64 that define
ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE, provided that the input was
page-aligned as in that case walk->offset == 0.

Fix it by reorganizing blkcipher_walk_done() to skip the
scatterwalk_advance() and scatterwalk_done() if an error has occurred.

This bug was found by syzkaller fuzzing.

Reproducer, assuming ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE:

#include <linux/if_alg.h>
#include <sys/socket.h>
#include <unistd.h>

int main()
{
struct sockaddr_alg addr = {
.salg_type = "skcipher",
.salg_name = "ecb(aes-generic)",
};
char buffer[4096] __attribute__((aligned(4096))) = { 0 };
int fd;

fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
bind(fd, (void *)&addr, sizeof(addr));
setsockopt(fd, SOL_ALG, ALG_SET_KEY, buffer, 16);
fd = accept(fd, NULL, NULL);
write(fd, buffer, 15);
read(fd, buffer, 15);
}

Reported-by: Liu Chao <liuchao741@huawei.com>
Fixes: 5cde0af2a982 ("[CRYPTO] cipher: Added block cipher type")
Cc: <stable@vger.kernel.org> # v2.6.19+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocrypto: vmac - separate tfm and request context
Eric Biggers [Mon, 18 Jun 2018 17:22:38 +0000 (10:22 -0700)]
crypto: vmac - separate tfm and request context

commit bb29648102335586e9a66289a1d98a0cb392b6e5 upstream.

syzbot reported a crash in vmac_final() when multiple threads
concurrently use the same "vmac(aes)" transform through AF_ALG.  The bug
is pretty fundamental: the VMAC template doesn't separate per-request
state from per-tfm (per-key) state like the other hash algorithms do,
but rather stores it all in the tfm context.  That's wrong.

Also, vmac_final() incorrectly zeroes most of the state including the
derived keys and cached pseudorandom pad.  Therefore, only the first
VMAC invocation with a given key calculates the correct digest.

Fix these bugs by splitting the per-tfm state from the per-request state
and using the proper init/update/final sequencing for requests.

Reproducer for the crash:

    #include <linux/if_alg.h>
    #include <sys/socket.h>
    #include <unistd.h>

    int main()
    {
            int fd;
            struct sockaddr_alg addr = {
                    .salg_type = "hash",
                    .salg_name = "vmac(aes)",
            };
            char buf[256] = { 0 };

            fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
            bind(fd, (void *)&addr, sizeof(addr));
            setsockopt(fd, SOL_ALG, ALG_SET_KEY, buf, 16);
            fork();
            fd = accept(fd, NULL, NULL);
            for (;;)
                    write(fd, buf, 256);
    }

The immediate cause of the crash is that vmac_ctx_t.partial_size exceeds
VMAC_NHBYTES, causing vmac_final() to memset() a negative length.

Reported-by: syzbot+264bca3a6e8d645550d3@syzkaller.appspotmail.com
Fixes: f1939f7c5645 ("crypto: vmac - New hash algorithm for intel_txt support")
Cc: <stable@vger.kernel.org> # v2.6.32+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocrypto: vmac - require a block cipher with 128-bit block size
Eric Biggers [Mon, 18 Jun 2018 17:22:37 +0000 (10:22 -0700)]
crypto: vmac - require a block cipher with 128-bit block size

commit 73bf20ef3df262026c3470241ae4ac8196943ffa upstream.

The VMAC template assumes the block cipher has a 128-bit block size, but
it failed to check for that.  Thus it was possible to instantiate it
using a 64-bit block size cipher, e.g. "vmac(cast5)", causing
uninitialized memory to be used.

Add the needed check when instantiating the template.

Fixes: f1939f7c5645 ("crypto: vmac - New hash algorithm for intel_txt support")
Cc: <stable@vger.kernel.org> # v2.6.32+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocrypto: x86/sha256-mb - fix digest copy in sha256_mb_mgr_get_comp_job_avx2()
Eric Biggers [Fri, 29 Jun 2018 21:14:35 +0000 (14:14 -0700)]
crypto: x86/sha256-mb - fix digest copy in sha256_mb_mgr_get_comp_job_avx2()

commit af839b4e546613aed1fbd64def73956aa98631e7 upstream.

There is a copy-paste error where sha256_mb_mgr_get_comp_job_avx2()
copies the SHA-256 digest state from sha256_mb_mgr::args::digest to
job_sha256::result_digest.  Consequently, the sha256_mb algorithm
sometimes calculates the wrong digest.  Fix it.

Reproducer using AF_ALG:

    #include <assert.h>
    #include <linux/if_alg.h>
    #include <stdio.h>
    #include <string.h>
    #include <sys/socket.h>
    #include <unistd.h>

    static const __u8 expected[32] =
        "\xad\x7f\xac\xb2\x58\x6f\xc6\xe9\x66\xc0\x04\xd7\xd1\xd1\x6b\x02"
        "\x4f\x58\x05\xff\x7c\xb4\x7c\x7a\x85\xda\xbd\x8b\x48\x89\x2c\xa7";

    int main()
    {
        int fd;
        struct sockaddr_alg addr = {
            .salg_type = "hash",
            .salg_name = "sha256_mb",
        };
        __u8 data[4096] = { 0 };
        __u8 digest[32];
        int ret;
        int i;

        fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
        bind(fd, (void *)&addr, sizeof(addr));
        fork();
        fd = accept(fd, 0, 0);
        do {
            ret = write(fd, data, 4096);
            assert(ret == 4096);
            ret = read(fd, digest, 32);
            assert(ret == 32);
        } while (memcmp(digest, expected, 32) == 0);

        printf("wrong digest: ");
        for (i = 0; i < 32; i++)
            printf("%02x", digest[i]);
        printf("\n");
    }

Output was:

    wrong digest: ad7facb2000000000000000000000000ffffffef7cb47c7a85dabd8b48892ca7

Fixes: 172b1d6b5a93 ("crypto: sha256-mb - fix ctx pointer and digest copy")
Cc: <stable@vger.kernel.org> # v4.8+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agokbuild: verify that $DEPMOD is installed
Randy Dunlap [Mon, 2 Jul 2018 02:46:06 +0000 (19:46 -0700)]
kbuild: verify that $DEPMOD is installed

commit 934193a654c1f4d0643ddbf4b2529b508cae926e upstream.

Verify that 'depmod' ($DEPMOD) is installed.
This is a partial revert of commit 620c231c7a7f
("kbuild: do not check for ancient modutils tools").

Also update Documentation/process/changes.rst to refer to
kmod instead of module-init-tools.

Fixes kernel bugzilla #198965:
https://bugzilla.kernel.org/show_bug.cgi?id=198965

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Lucas De Marchi <lucas.demarchi@profusion.mobi>
Cc: Lucas De Marchi <lucas.de.marchi@gmail.com>
Cc: Michal Marek <michal.lkml@markovi.net>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Chih-Wei Huang <cwhuang@linux.org.tw>
Cc: stable@vger.kernel.org # any kernel since 2012
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/mm: Disable ioremap free page handling on x86-PAE
Toshi Kani [Wed, 27 Jun 2018 14:13:46 +0000 (08:13 -0600)]
x86/mm: Disable ioremap free page handling on x86-PAE

commit f967db0b9ed44ec3057a28f3b28efc51df51b835 upstream.

ioremap() supports pmd mappings on x86-PAE.  However, kernel's pmd
tables are not shared among processes on x86-PAE.  Therefore, any
update to sync'd pmd entries need re-syncing.  Freeing a pte page
also leads to a vmalloc fault and hits the BUG_ON in vmalloc_sync_one().

Disable free page handling on x86-PAE.  pud_free_pmd_page() and
pmd_free_pte_page() simply return 0 if a given pud/pmd entry is present.
This assures that ioremap() does not update sync'd pmd entries at the
cost of falling back to pte mappings.

Fixes: 28ee90fe6048 ("x86/mm: implement free pmd/pte page interfaces")
Reported-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: mhocko@suse.com
Cc: akpm@linux-foundation.org
Cc: hpa@zytor.com
Cc: cpandya@codeaurora.org
Cc: linux-mm@kvack.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: stable@vger.kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20180627141348.21777-2-toshi.kani@hpe.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86: i8259: Add missing include file
Guenter Roeck [Wed, 15 Aug 2018 20:22:27 +0000 (13:22 -0700)]
x86: i8259: Add missing include file

commit 0a957467c5fd46142bc9c52758ffc552d4c5e2f7 upstream.

i8259.h uses inb/outb and thus needs to include asm/io.h to avoid the
following build error, as seen with x86_64:defconfig and CONFIG_SMP=n.

  In file included from drivers/rtc/rtc-cmos.c:45:0:
  arch/x86/include/asm/i8259.h: In function 'inb_pic':
  arch/x86/include/asm/i8259.h:32:24: error:
implicit declaration of function 'inb'

  arch/x86/include/asm/i8259.h: In function 'outb_pic':
  arch/x86/include/asm/i8259.h:45:2: error:
implicit declaration of function 'outb'

Reported-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Suggested-by: Sebastian Gottschall <s.gottschall@dd-wrt.com>
Fixes: 447ae3166702 ("x86: Don't include linux/irq.h from asm/hardirq.h")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/l1tf: Fix build error seen if CONFIG_KVM_INTEL is disabled
Guenter Roeck [Wed, 15 Aug 2018 15:38:33 +0000 (08:38 -0700)]
x86/l1tf: Fix build error seen if CONFIG_KVM_INTEL is disabled

commit 1eb46908b35dfbac0ec1848d4b1e39667e0187e9 upstream.

allmodconfig+CONFIG_INTEL_KVM=n results in the following build error.

  ERROR: "l1tf_vmx_mitigation" [arch/x86/kvm/kvm.ko] undefined!

Fixes: 5b76a3cff011 ("KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry")
Reported-by: Meelis Roos <mroos@linux.ee>
Cc: Meelis Roos <mroos@linux.ee>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoLinux 4.14.63
Greg Kroah-Hartman [Wed, 15 Aug 2018 16:13:02 +0000 (18:13 +0200)]
Linux 4.14.63

6 years agox86/CPU/AMD: Have smp_num_siblings and cpu_llc_id always be present
Borislav Petkov [Fri, 27 Apr 2018 21:34:34 +0000 (16:34 -0500)]
x86/CPU/AMD: Have smp_num_siblings and cpu_llc_id always be present

commit f8b64d08dde2714c62751d18ba77f4aeceb161d3 upstream.

Move smp_num_siblings and cpu_llc_id to cpu/common.c so that they're
always present as symbols and not only in the CONFIG_SMP case. Then,
other code using them doesn't need ugly ifdeffery anymore. Get rid of
some ifdeffery.

Signed-off-by: Borislav Petkov <bpetkov@suse.de>
Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1524864877-111962-2-git-send-email-suravee.suthikulpanit@amd.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/speculation/l1tf: Unbreak !__HAVE_ARCH_PFN_MODIFY_ALLOWED architectures
Jiri Kosina [Sat, 14 Jul 2018 19:56:13 +0000 (21:56 +0200)]
x86/speculation/l1tf: Unbreak !__HAVE_ARCH_PFN_MODIFY_ALLOWED architectures

commit 6c26fcd2abfe0a56bbd95271fce02df2896cfd24 upstream.

pfn_modify_allowed() and arch_has_pfn_modify_check() are outside of the
!__ASSEMBLY__ section in include/asm-generic/pgtable.h, which confuses
assembler on archs that don't have __HAVE_ARCH_PFN_MODIFY_ALLOWED (e.g.
ia64) and breaks build:

    include/asm-generic/pgtable.h: Assembler messages:
    include/asm-generic/pgtable.h:538: Error: Unknown opcode `static inline bool pfn_modify_allowed(unsigned long pfn,pgprot_t prot)'
    include/asm-generic/pgtable.h:540: Error: Unknown opcode `return true'
    include/asm-generic/pgtable.h:543: Error: Unknown opcode `static inline bool arch_has_pfn_modify_check(void)'
    include/asm-generic/pgtable.h:545: Error: Unknown opcode `return false'
    arch/ia64/kernel/entry.S:69: Error: `mov' does not fit into bundle

Move those two static inlines into the !__ASSEMBLY__ section so that they
don't confuse the asm build pass.

Fixes: 42e4089c7890 ("x86/speculation/l1tf: Disallow non privileged high MMIO PROT_NONE mappings")
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/init: fix build with CONFIG_SWAP=n
Vlastimil Babka [Tue, 14 Aug 2018 18:50:47 +0000 (20:50 +0200)]
x86/init: fix build with CONFIG_SWAP=n

commit 792adb90fa724ce07c0171cbc96b9215af4b1045 upstream.

The introduction of generic_max_swapfile_size and arch-specific versions has
broken linking on x86 with CONFIG_SWAP=n due to undefined reference to
'generic_max_swapfile_size'. Fix it by compiling the x86-specific
max_swapfile_size() only with CONFIG_SWAP=y.

Reported-by: Tomas Pruzina <pruzinat@gmail.com>
Fixes: 377eeaa8e11f ("x86/speculation/l1tf: Limit swap file size to MAX_PA/2")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocpu/hotplug: Non-SMP machines do not make use of booted_once
Abel Vesa [Tue, 14 Aug 2018 21:26:00 +0000 (00:26 +0300)]
cpu/hotplug: Non-SMP machines do not make use of booted_once

commit 269777aa530f3438ec1781586cdac0b5fe47b061 upstream.

Commit 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once")
breaks non-SMP builds.

[ I suspect the 'bool' fields should just be made to be bitfields and be
  exposed regardless of configuration, but that's a separate cleanup
  that I'll leave to the owners of this file for later.   - Linus ]

Fixes: 0cc3cd21657b ("cpu/hotplug: Boot HT siblings at least once")
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Abel Vesa <abelvesa@linux.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/smp: fix non-SMP broken build due to redefinition of apic_id_is_primary_thread
Vlastimil Babka [Tue, 14 Aug 2018 21:38:57 +0000 (23:38 +0200)]
x86/smp: fix non-SMP broken build due to redefinition of apic_id_is_primary_thread

commit d0055f351e647f33f3b0329bff022213bf8aa085 upstream.

The function has an inline "return false;" definition with CONFIG_SMP=n
but the "real" definition is also visible leading to "redefinition of
‘apic_id_is_primary_thread’" compiler error.

Guard it with #ifdef CONFIG_SMP

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Fixes: 6a4d2657e048 ("x86/smp: Provide topology_is_primary_thread()")
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/microcode: Allow late microcode loading with SMT disabled
Josh Poimboeuf [Fri, 10 Aug 2018 07:31:10 +0000 (08:31 +0100)]
x86/microcode: Allow late microcode loading with SMT disabled

commit 07d981ad4cf1e78361c6db1c28ee5ba105f96cc1 upstream

The kernel unnecessarily prevents late microcode loading when SMT is
disabled.  It should be safe to allow it if all the primary threads are
online.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agotools headers: Synchronise x86 cpufeatures.h for L1TF additions
David Woodhouse [Wed, 8 Aug 2018 10:00:16 +0000 (11:00 +0100)]
tools headers: Synchronise x86 cpufeatures.h for L1TF additions

commit e24f14b0ff985f3e09e573ba1134bfdf42987e05 upstream

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/mm/kmmio: Make the tracer robust against L1TF
Andi Kleen [Tue, 7 Aug 2018 22:09:38 +0000 (15:09 -0700)]
x86/mm/kmmio: Make the tracer robust against L1TF

commit 1063711b57393c1999248cccb57bebfaf16739e7 upstream

The mmio tracer sets io mapping PTEs and PMDs to non present when enabled
without inverting the address bits, which makes the PTE entry vulnerable
for L1TF.

Make it use the right low level macros to actually invert the address bits
to protect against L1TF.

In principle this could be avoided because MMIO tracing is not likely to be
enabled on production machines, but the fix is straigt forward and for
consistency sake it's better to get rid of the open coded PTE manipulation.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/mm/pat: Make set_memory_np() L1TF safe
Andi Kleen [Tue, 7 Aug 2018 22:09:39 +0000 (15:09 -0700)]
x86/mm/pat: Make set_memory_np() L1TF safe

commit 958f79b9ee55dfaf00c8106ed1c22a2919e0028b upstream

set_memory_np() is used to mark kernel mappings not present, but it has
it's own open coded mechanism which does not have the L1TF protection of
inverting the address bits.

Replace the open coded PTE manipulation with the L1TF protecting low level
PTE routines.

Passes the CPA self test.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/speculation/l1tf: Make pmd/pud_mknotpresent() invert
Andi Kleen [Tue, 7 Aug 2018 22:09:37 +0000 (15:09 -0700)]
x86/speculation/l1tf: Make pmd/pud_mknotpresent() invert

commit 0768f91530ff46683e0b372df14fd79fe8d156e5 upstream

Some cases in THP like:
  - MADV_FREE
  - mprotect
  - split

mark the PMD non present for temporarily to prevent races. The window for
an L1TF attack in these contexts is very small, but it wants to be fixed
for correctness sake.

Use the proper low level functions for pmd/pud_mknotpresent() to address
this.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/speculation/l1tf: Invert all not present mappings
Andi Kleen [Tue, 7 Aug 2018 22:09:36 +0000 (15:09 -0700)]
x86/speculation/l1tf: Invert all not present mappings

commit f22cc87f6c1f771b57c407555cfefd811cdd9507 upstream

For kernel mappings PAGE_PROTNONE is not necessarily set for a non present
mapping, but the inversion logic explicitely checks for !PRESENT and
PROT_NONE.

Remove the PROT_NONE check and make the inversion unconditional for all not
present mappings.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocpu/hotplug: Fix SMT supported evaluation
Thomas Gleixner [Tue, 7 Aug 2018 06:19:57 +0000 (08:19 +0200)]
cpu/hotplug: Fix SMT supported evaluation

commit bc2d8d262cba5736332cbc866acb11b1c5748aa9 upstream

Josh reported that the late SMT evaluation in cpu_smt_state_init() sets
cpu_smt_control to CPU_SMT_NOT_SUPPORTED in case that 'nosmt' was supplied
on the kernel command line as it cannot differentiate between SMT disabled
by BIOS and SMT soft disable via 'nosmt'. That wreckages the state and
makes the sysfs interface unusable.

Rework this so that during bringup of the non boot CPUs the availability of
SMT is determined in cpu_smt_allowed(). If a newly booted CPU is not a
'primary' thread then set the local cpu_smt_available marker and evaluate
this explicitely right after the initial SMP bringup has finished.

SMT evaulation on x86 is a trainwreck as the firmware has all the
information _before_ booting the kernel, but there is no interface to query
it.

Fixes: 73d5e2b47264 ("cpu/hotplug: detect SMT disabled by BIOS")
Reported-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoKVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry
Paolo Bonzini [Sun, 5 Aug 2018 14:07:47 +0000 (16:07 +0200)]
KVM: VMX: Tell the nested hypervisor to skip L1D flush on vmentry

commit 5b76a3cff011df2dcb6186c965a2e4d809a05ad4 upstream

When nested virtualization is in use, VMENTER operations from the nested
hypervisor into the nested guest will always be processed by the bare metal
hypervisor, and KVM's "conditional cache flushes" mode in particular does a
flush on nested vmentry.  Therefore, include the "skip L1D flush on
vmentry" bit in KVM's suggested ARCH_CAPABILITIES setting.

Add the relevant Documentation.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/speculation: Use ARCH_CAPABILITIES to skip L1D flush on vmentry
Paolo Bonzini [Sun, 5 Aug 2018 14:07:46 +0000 (16:07 +0200)]
x86/speculation: Use ARCH_CAPABILITIES to skip L1D flush on vmentry

commit 8e0b2b916662e09dd4d09e5271cdf214c6b80e62 upstream

Bit 3 of ARCH_CAPABILITIES tells a hypervisor that L1D flush on vmentry is
not needed.  Add a new value to enum vmx_l1d_flush_state, which is used
either if there is no L1TF bug at all, or if bit 3 is set in ARCH_CAPABILITIES.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/speculation: Simplify sysfs report of VMX L1TF vulnerability
Paolo Bonzini [Sun, 5 Aug 2018 14:07:45 +0000 (16:07 +0200)]
x86/speculation: Simplify sysfs report of VMX L1TF vulnerability

commit ea156d192f5257a5bf393d33910d3b481bf8a401 upstream

Three changes to the content of the sysfs file:

 - If EPT is disabled, L1TF cannot be exploited even across threads on the
   same core, and SMT is irrelevant.

 - If mitigation is completely disabled, and SMT is enabled, print "vulnerable"
   instead of "vulnerable, SMT vulnerable"

 - Reorder the two parts so that the main vulnerability state comes first
   and the detail on SMT is second.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoKVM: VMX: support MSR_IA32_ARCH_CAPABILITIES as a feature MSR
Paolo Bonzini [Mon, 25 Jun 2018 12:04:37 +0000 (14:04 +0200)]
KVM: VMX: support MSR_IA32_ARCH_CAPABILITIES as a feature MSR

commit cd28325249a1ca0d771557ce823e0308ad629f98 upstream

This lets userspace read the MSR_IA32_ARCH_CAPABILITIES and check that all
requested features are available on the host.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoKVM: X86: Allow userspace to define the microcode version
Wanpeng Li [Wed, 28 Feb 2018 06:03:31 +0000 (14:03 +0800)]
KVM: X86: Allow userspace to define the microcode version

commit 518e7b94817abed94becfe6a44f1ece0d4745afe upstream

Linux (among the others) has checks to make sure that certain features
aren't enabled on a certain family/model/stepping if the microcode version
isn't greater than or equal to a known good version.

By exposing the real microcode version, we're preventing buggy guests that
don't check that they are running virtualized (i.e., they should trust the
hypervisor) from disabling features that are effectively not buggy.

Suggested-by: Filippo Sironi <sironi@amazon.de>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoKVM: X86: Introduce kvm_get_msr_feature()
Wanpeng Li [Wed, 28 Feb 2018 06:03:30 +0000 (14:03 +0800)]
KVM: X86: Introduce kvm_get_msr_feature()

commit 66421c1ec340096b291af763ed5721314cdd9c5c upstream

Introduce kvm_get_msr_feature() to handle the msrs which are supported
by different vendors and sharing the same emulation logic.

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Cc: Liran Alon <liran.alon@oracle.com>
Cc: Nadav Amit <nadav.amit@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoKVM: SVM: Add MSR-based feature support for serializing LFENCE
Tom Lendacky [Fri, 23 Feb 2018 23:18:20 +0000 (00:18 +0100)]
KVM: SVM: Add MSR-based feature support for serializing LFENCE

commit d1d93fa90f1afa926cb060b7f78ab01a65705b4d upstream

In order to determine if LFENCE is a serializing instruction on AMD
processors, MSR 0xc0011029 (MSR_F10H_DECFG) must be read and the state
of bit 1 checked.  This patch will add support to allow a guest to
properly make this determination.

Add the MSR feature callback operation to svm.c and add MSR 0xc0011029
to the list of MSR-based features.  If LFENCE is serializing, then the
feature is supported, allowing the hypervisor to set the value of the
MSR that guest will see.  Support is also added to write (hypervisor only)
and read the MSR value for the guest.  A write by the guest will result in
a #GP.  A read by the guest will return the value as set by the host.  In
this way, the support to expose the feature to the guest is controlled by
the hypervisor.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoKVM: x86: Add a framework for supporting MSR-based features
Tom Lendacky [Wed, 21 Feb 2018 19:39:51 +0000 (13:39 -0600)]
KVM: x86: Add a framework for supporting MSR-based features

commit 801e459a6f3a63af9d447e6249088c76ae16efc4 upstream

Provide a new KVM capability that allows bits within MSRs to be recognized
as features.  Two new ioctls are added to the /dev/kvm ioctl routine to
retrieve the list of these MSRs and then retrieve their values. A kvm_x86_ops
callback is used to determine support for the listed MSR-based features.

Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[Tweaked documentation. - Radim]
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoDocumentation/l1tf: Remove Yonah processors from not vulnerable list
Thomas Gleixner [Sun, 5 Aug 2018 15:06:12 +0000 (17:06 +0200)]
Documentation/l1tf: Remove Yonah processors from not vulnerable list

commit 58331136136935c631c2b5f06daf4c3006416e91 upstream

Dave reported, that it's not confirmed that Yonah processors are
unaffected. Remove them from the list.

Reported-by: ave Hansen <dave.hansen@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Don't set l1tf_flush_l1d from vmx_handle_external_intr()
Nicolai Stange [Sun, 22 Jul 2018 11:38:18 +0000 (13:38 +0200)]
x86/KVM/VMX: Don't set l1tf_flush_l1d from vmx_handle_external_intr()

commit 18b57ce2eb8c8b9a24174a89250cf5f57c76ecdc upstream

For VMEXITs caused by external interrupts, vmx_handle_external_intr()
indirectly calls into the interrupt handlers through the host's IDT.

It follows that these interrupts get accounted for in the
kvm_cpu_l1tf_flush_l1d per-cpu flag.

The subsequently executed vmx_l1d_flush() will thus be aware that some
interrupts have happened and conduct a L1d flush anyway.

Setting l1tf_flush_l1d from vmx_handle_external_intr() isn't needed
anymore. Drop it.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d
Nicolai Stange [Sun, 29 Jul 2018 11:06:04 +0000 (13:06 +0200)]
x86/irq: Let interrupt handlers set kvm_cpu_l1tf_flush_l1d

commit ffcba43ff66c7dab34ec700debd491d2a4d319b4 upstream

The last missing piece to having vmx_l1d_flush() take interrupts after
VMEXIT into account is to set the kvm_cpu_l1tf_flush_l1d per-cpu flag on
irq entry.

Issue calls to kvm_set_cpu_l1tf_flush_l1d() from entering_irq(),
ipi_entering_ack_irq(), smp_reschedule_interrupt() and
uv_bau_message_interrupt().

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86: Don't include linux/irq.h from asm/hardirq.h
Nicolai Stange [Sun, 29 Jul 2018 10:15:33 +0000 (12:15 +0200)]
x86: Don't include linux/irq.h from asm/hardirq.h

commit 447ae316670230d7d29430e2cbf1f5db4f49d14c upstream

The next patch in this series will have to make the definition of
irq_cpustat_t available to entering_irq().

Inclusion of asm/hardirq.h into asm/apic.h would cause circular header
dependencies like

  asm/smp.h
    asm/apic.h
      asm/hardirq.h
        linux/irq.h
          linux/topology.h
            linux/smp.h
              asm/smp.h

or

  linux/gfp.h
    linux/mmzone.h
      asm/mmzone.h
        asm/mmzone_64.h
          asm/smp.h
            asm/apic.h
              asm/hardirq.h
                linux/irq.h
                  linux/irqdesc.h
                    linux/kobject.h
                      linux/sysfs.h
                        linux/kernfs.h
                          linux/idr.h
                            linux/gfp.h

and others.

This causes compilation errors because of the header guards becoming
effective in the second inclusion: symbols/macros that had been defined
before wouldn't be available to intermediate headers in the #include chain
anymore.

A possible workaround would be to move the definition of irq_cpustat_t
into its own header and include that from both, asm/hardirq.h and
asm/apic.h.

However, this wouldn't solve the real problem, namely asm/harirq.h
unnecessarily pulling in all the linux/irq.h cruft: nothing in
asm/hardirq.h itself requires it. Also, note that there are some other
archs, like e.g. arm64, which don't have that #include in their
asm/hardirq.h.

Remove the linux/irq.h #include from x86' asm/hardirq.h.

Fix resulting compilation errors by adding appropriate #includes to *.c
files as needed.

Note that some of these *.c files could be cleaned up a bit wrt. to their
set of #includes, but that should better be done from separate patches, if
at all.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Introduce per-host-cpu analogue of l1tf_flush_l1d
Nicolai Stange [Fri, 27 Jul 2018 11:22:16 +0000 (13:22 +0200)]
x86/KVM/VMX: Introduce per-host-cpu analogue of l1tf_flush_l1d

commit 45b575c00d8e72d69d75dd8c112f044b7b01b069 upstream

Part of the L1TF mitigation for vmx includes flushing the L1D cache upon
VMENTRY.

L1D flushes are costly and two modes of operations are provided to users:
"always" and the more selective "conditional" mode.

If operating in the latter, the cache would get flushed only if a host side
code path considered unconfined had been traversed. "Unconfined" in this
context means that it might have pulled in sensitive data like user data
or kernel crypto keys.

The need for L1D flushes is tracked by means of the per-vcpu flag
l1tf_flush_l1d. KVM exit handlers considered unconfined set it. A
vmx_l1d_flush() subsequently invoked before the next VMENTER will conduct a
L1d flush based on its value and reset that flag again.

Currently, interrupts delivered "normally" while in root operation between
VMEXIT and VMENTER are not taken into account. Part of the reason is that
these don't leave any traces and thus, the vmx code is unable to tell if
any such has happened.

As proposed by Paolo Bonzini, prepare for tracking all interrupts by
introducing a new per-cpu flag, "kvm_cpu_l1tf_flush_l1d". It will be in
strong analogy to the per-vcpu ->l1tf_flush_l1d.

A later patch will make interrupt handlers set it.

For the sake of cache locality, group kvm_cpu_l1tf_flush_l1d into x86'
per-cpu irq_cpustat_t as suggested by Peter Zijlstra.

Provide the helpers kvm_set_cpu_l1tf_flush_l1d(),
kvm_clear_cpu_l1tf_flush_l1d() and kvm_get_cpu_l1tf_flush_l1d(). Make them
trivial resp. non-existent for !CONFIG_KVM_INTEL as appropriate.

Let vmx_l1d_flush() handle kvm_cpu_l1tf_flush_l1d in the same way as
l1tf_flush_l1d.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/irq: Demote irq_cpustat_t::__softirq_pending to u16
Nicolai Stange [Fri, 27 Jul 2018 10:46:29 +0000 (12:46 +0200)]
x86/irq: Demote irq_cpustat_t::__softirq_pending to u16

commit 9aee5f8a7e30330d0a8f4c626dc924ca5590aba5 upstream

An upcoming patch will extend KVM's L1TF mitigation in conditional mode
to also cover interrupts after VMEXITs. For tracking those, stores to a
new per-cpu flag from interrupt handlers will become necessary.

In order to improve cache locality, this new flag will be added to x86's
irq_cpustat_t.

Make some space available there by shrinking the ->softirq_pending bitfield
from 32 to 16 bits: the number of bits actually used is only NR_SOFTIRQS,
i.e. 10.

Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Move the l1tf_flush_l1d test to vmx_l1d_flush()
Nicolai Stange [Sat, 21 Jul 2018 20:35:28 +0000 (22:35 +0200)]
x86/KVM/VMX: Move the l1tf_flush_l1d test to vmx_l1d_flush()

commit 5b6ccc6c3b1a477fbac9ec97a0b4c1c48e765209 upstream

Currently, vmx_vcpu_run() checks if l1tf_flush_l1d is set and invokes
vmx_l1d_flush() if so.

This test is unncessary for the "always flush L1D" mode.

Move the check to vmx_l1d_flush()'s conditional mode code path.

Notes:
- vmx_l1d_flush() is likely to get inlined anyway and thus, there's no
  extra function call.

- This inverts the (static) branch prediction, but there hadn't been any
  explicit likely()/unlikely() annotations before and so it stays as is.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Replace 'vmx_l1d_flush_always' with 'vmx_l1d_flush_cond'
Nicolai Stange [Sat, 21 Jul 2018 20:25:00 +0000 (22:25 +0200)]
x86/KVM/VMX: Replace 'vmx_l1d_flush_always' with 'vmx_l1d_flush_cond'

commit 427362a142441f08051369db6fbe7f61c73b3dca upstream

The vmx_l1d_flush_always static key is only ever evaluated if
vmx_l1d_should_flush is enabled. In that case however, there are only two
L1d flushing modes possible: "always" and "conditional".

The "conditional" mode's implementation tends to require more sophisticated
logic than the "always" mode.

Avoid inverted logic by replacing the 'vmx_l1d_flush_always' static key
with a 'vmx_l1d_flush_cond' one.

There is no change in functionality.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Don't set l1tf_flush_l1d to true from vmx_l1d_flush()
Nicolai Stange [Sat, 21 Jul 2018 20:16:56 +0000 (22:16 +0200)]
x86/KVM/VMX: Don't set l1tf_flush_l1d to true from vmx_l1d_flush()

commit 379fd0c7e6a391e5565336a646f19f218fb98c6c upstream

vmx_l1d_flush() gets invoked only if l1tf_flush_l1d is true. There's no
point in setting l1tf_flush_l1d to true from there again.

Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocpu/hotplug: detect SMT disabled by BIOS
Josh Poimboeuf [Wed, 25 Jul 2018 08:36:45 +0000 (10:36 +0200)]
cpu/hotplug: detect SMT disabled by BIOS

commit 73d5e2b472640b1fcdb61ae8be389912ef211bda upstream

If SMT is disabled in BIOS, the CPU code doesn't properly detect it.
The /sys/devices/system/cpu/smt/control file shows 'on', and the 'l1tf'
vulnerabilities file shows SMT as vulnerable.

Fix it by forcing 'cpu_smt_control' to CPU_SMT_NOT_SUPPORTED in such a
case.  Unfortunately the detection can only be done after bringing all
the CPUs online, so we have to overwrite any previous writes to the
variable.

Reported-by: Joe Mario <jmario@redhat.com>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Fixes: f048c399e0f7 ("x86/topology: Provide topology_smt_supported()")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoDocumentation/l1tf: Fix typos
Tony Luck [Thu, 19 Jul 2018 20:49:58 +0000 (13:49 -0700)]
Documentation/l1tf: Fix typos

commit 1949f9f49792d65dba2090edddbe36a5f02e3ba3 upstream

Fix spelling and other typos

Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Initialize the vmx_l1d_flush_pages' content
Nicolai Stange [Wed, 18 Jul 2018 17:07:38 +0000 (19:07 +0200)]
x86/KVM/VMX: Initialize the vmx_l1d_flush_pages' content

commit 288d152c23dcf3c09da46c5c481903ca10ebfef7 upstream

The slow path in vmx_l1d_flush() reads from vmx_l1d_flush_pages in order
to evict the L1d cache.

However, these pages are never cleared and, in theory, their data could be
leaked.

More importantly, KSM could merge a nested hypervisor's vmx_l1d_flush_pages
to fewer than 1 << L1D_CACHE_ORDER host physical pages and this would break
the L1d flushing algorithm: L1D on x86_64 is tagged by physical addresses.

Fix this by initializing the individual vmx_l1d_flush_pages with a
different pattern each.

Rename the "empty_zp" asm constraint identifier in vmx_l1d_flush() to
"flush_pages" to reflect this change.

Fixes: a47dd5f06714 ("x86/KVM/VMX: Add L1D flush algorithm")
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoDocumentation: Add section about CPU vulnerabilities
Thomas Gleixner [Fri, 13 Jul 2018 14:23:26 +0000 (16:23 +0200)]
Documentation: Add section about CPU vulnerabilities

commit 3ec8ce5d866ec6a08a9cfab82b62acf4a830b35f upstream

Add documentation for the L1TF vulnerability and the mitigation mechanisms:

  - Explain the problem and risks
  - Document the mitigation mechanisms
  - Document the command line controls
  - Document the sysfs files

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lkml.kernel.org/r/20180713142323.287429944@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/bugs, kvm: Introduce boot-time control of L1TF mitigations
Jiri Kosina [Fri, 13 Jul 2018 14:23:25 +0000 (16:23 +0200)]
x86/bugs, kvm: Introduce boot-time control of L1TF mitigations

commit d90a7a0ec83fb86622cd7dae23255d3c50a99ec8 upstream

Introduce the 'l1tf=' kernel command line option to allow for boot-time
switching of mitigation that is used on processors affected by L1TF.

The possible values are:

  full
Provides all available mitigations for the L1TF vulnerability. Disables
SMT and enables all mitigations in the hypervisors. SMT control via
/sys/devices/system/cpu/smt/control is still possible after boot.
Hypervisors will issue a warning when the first VM is started in
a potentially insecure configuration, i.e. SMT enabled or L1D flush
disabled.

  full,force
Same as 'full', but disables SMT control. Implies the 'nosmt=force'
command line option. sysfs control of SMT and the hypervisor flush
control is disabled.

  flush
Leaves SMT enabled and enables the conditional hypervisor mitigation.
Hypervisors will issue a warning when the first VM is started in a
potentially insecure configuration, i.e. SMT enabled or L1D flush
disabled.

  flush,nosmt
Disables SMT and enables the conditional hypervisor mitigation. SMT
control via /sys/devices/system/cpu/smt/control is still possible
after boot. If SMT is reenabled or flushing disabled at runtime
hypervisors will issue a warning.

  flush,nowarn
Same as 'flush', but hypervisors will not warn when
a VM is started in a potentially insecure configuration.

  off
Disables hypervisor mitigations and doesn't emit any warnings.

Default is 'flush'.

Let KVM adhere to these semantics, which means:

  - 'lt1f=full,force' : Performe L1D flushes. No runtime control
       possible.

  - 'l1tf=full'
  - 'l1tf-flush'
  - 'l1tf=flush,nosmt' : Perform L1D flushes and warn on VM start if
  SMT has been runtime enabled or L1D flushing
  has been run-time enabled

  - 'l1tf=flush,nowarn' : Perform L1D flushes and no warnings are emitted.

  - 'l1tf=off' : L1D flushes are not performed and no warnings
  are emitted.

KVM can always override the L1D flushing behavior using its 'vmentry_l1d_flush'
module parameter except when lt1f=full,force is set.

This makes KVM's private 'nosmt' option redundant, and as it is a bit
non-systematic anyway (this is something to control globally, not on
hypervisor level), remove that option.

Add the missing Documentation entry for the l1tf vulnerability sysfs file
while at it.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142323.202758176@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocpu/hotplug: Set CPU_SMT_NOT_SUPPORTED early
Thomas Gleixner [Fri, 13 Jul 2018 14:23:24 +0000 (16:23 +0200)]
cpu/hotplug: Set CPU_SMT_NOT_SUPPORTED early

commit fee0aede6f4739c87179eca76136f83210953b86 upstream

The CPU_SMT_NOT_SUPPORTED state is set (if the processor does not support
SMT) when the sysfs SMT control file is initialized.

That was fine so far as this was only required to make the output of the
control file correct and to prevent writes in that case.

With the upcoming l1tf command line parameter, this needs to be set up
before the L1TF mitigation selection and command line parsing happens.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142323.121795971@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocpu/hotplug: Expose SMT control init function
Jiri Kosina [Fri, 13 Jul 2018 14:23:23 +0000 (16:23 +0200)]
cpu/hotplug: Expose SMT control init function

commit 8e1b706b6e819bed215c0db16345568864660393 upstream

The L1TF mitigation will gain a commend line parameter which allows to set
a combination of hypervisor mitigation and SMT control.

Expose cpu_smt_disable() so the command line parser can tweak SMT settings.

[ tglx: Split out of larger patch and made it preserve an already existing
   force off state ]

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142323.039715135@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/kvm: Allow runtime control of L1D flush
Thomas Gleixner [Fri, 13 Jul 2018 14:23:22 +0000 (16:23 +0200)]
x86/kvm: Allow runtime control of L1D flush

commit 895ae47f9918833c3a880fbccd41e0692b37e7d9 upstream

All mitigation modes can be switched at run time with a static key now:

 - Use sysfs_streq() instead of strcmp() to handle the trailing new line
   from sysfs writes correctly.
 - Make the static key management handle multiple invocations properly.
 - Set the module parameter file to RW

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142322.954525119@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/kvm: Serialize L1D flush parameter setter
Thomas Gleixner [Fri, 13 Jul 2018 14:23:21 +0000 (16:23 +0200)]
x86/kvm: Serialize L1D flush parameter setter

commit dd4bfa739a72508b75760b393d129ed7b431daab upstream

Writes to the parameter files are not serialized at the sysfs core
level, so local serialization is required.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142322.873642605@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/kvm: Add static key for flush always
Thomas Gleixner [Fri, 13 Jul 2018 14:23:20 +0000 (16:23 +0200)]
x86/kvm: Add static key for flush always

commit 4c6523ec59fe895ea352a650218a6be0653910b1 upstream

Avoid the conditional in the L1D flush control path.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142322.790914912@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/kvm: Move l1tf setup function
Thomas Gleixner [Fri, 13 Jul 2018 14:23:19 +0000 (16:23 +0200)]
x86/kvm: Move l1tf setup function

commit 7db92e165ac814487264632ab2624e832f20ae38 upstream

In preparation of allowing run time control for L1D flushing, move the
setup code to the module parameter handler.

In case of pre module init parsing, just store the value and let vmx_init()
do the actual setup after running kvm_init() so that enable_ept is having
the correct state.

During run-time invoke it directly from the parameter setter to prepare for
run-time control.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142322.694063239@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/l1tf: Handle EPT disabled state proper
Thomas Gleixner [Fri, 13 Jul 2018 14:23:18 +0000 (16:23 +0200)]
x86/l1tf: Handle EPT disabled state proper

commit a7b9020b06ec6d7c3f3b0d4ef1a9eba12654f4f7 upstream

If Extended Page Tables (EPT) are disabled or not supported, no L1D
flushing is required. The setup function can just avoid setting up the L1D
flush for the EPT=n case.

Invoke it after the hardware setup has be done and enable_ept has the
correct state and expose the EPT disabled state in the mitigation status as
well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142322.612160168@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/kvm: Drop L1TF MSR list approach
Thomas Gleixner [Fri, 13 Jul 2018 14:23:17 +0000 (16:23 +0200)]
x86/kvm: Drop L1TF MSR list approach

commit 2f055947ae5e2741fb2dc5bba1033c417ccf4faa upstream

The VMX module parameter to control the L1D flush should become
writeable.

The MSR list is set up at VM init per guest VCPU, but the run time
switching is based on a static key which is global. Toggling the MSR list
at run time might be feasible, but for now drop this optimization and use
the regular MSR write to make run-time switching possible.

The default mitigation is the conditional flush anyway, so for extra
paranoid setups this will add some small overhead, but the extra code
executed is in the noise compared to the flush itself.

Aside of that the EPT disabled case is not handled correctly at the moment
and the MSR list magic is in the way for fixing that as well.

If it's really providing a significant advantage, then this needs to be
revisited after the code is correct and the control is writable.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142322.516940445@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/litf: Introduce vmx status variable
Thomas Gleixner [Fri, 13 Jul 2018 14:23:16 +0000 (16:23 +0200)]
x86/litf: Introduce vmx status variable

commit 72c6d2db64fa18c996ece8f06e499509e6c9a37e upstream

Store the effective mitigation of VMX in a status variable and use it to
report the VMX state in the l1tf sysfs file.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lkml.kernel.org/r/20180713142322.433098358@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocpu/hotplug: Online siblings when SMT control is turned on
Thomas Gleixner [Sat, 7 Jul 2018 09:40:18 +0000 (11:40 +0200)]
cpu/hotplug: Online siblings when SMT control is turned on

commit 215af5499d9e2b55f111d2431ea20218115f29b3 upstream

Writing 'off' to /sys/devices/system/cpu/smt/control offlines all SMT
siblings. Writing 'on' merily enables the abilify to online them, but does
not online them automatically.

Make 'on' more useful by onlining all offline siblings.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Use MSR save list for IA32_FLUSH_CMD if required
Konrad Rzeszutek Wilk [Thu, 28 Jun 2018 21:10:36 +0000 (17:10 -0400)]
x86/KVM/VMX: Use MSR save list for IA32_FLUSH_CMD if required

commit 390d975e0c4e60ce70d4157e0dd91ede37824603 upstream

If the L1D flush module parameter is set to 'always' and the IA32_FLUSH_CMD
MSR is available, optimize the VMENTER code with the MSR save list.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Extend add_atomic_switch_msr() to allow VMENTER only MSRs
Konrad Rzeszutek Wilk [Thu, 21 Jun 2018 02:01:22 +0000 (22:01 -0400)]
x86/KVM/VMX: Extend add_atomic_switch_msr() to allow VMENTER only MSRs

commit 989e3992d2eca32c3f1404f2bc91acda3aa122d8 upstream

The IA32_FLUSH_CMD MSR needs only to be written on VMENTER. Extend
add_atomic_switch_msr() with an entry_only parameter to allow storing the
MSR only in the guest (ENTRY) MSR array.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Separate the VMX AUTOLOAD guest/host number accounting
Konrad Rzeszutek Wilk [Thu, 21 Jun 2018 02:00:47 +0000 (22:00 -0400)]
x86/KVM/VMX: Separate the VMX AUTOLOAD guest/host number accounting

commit 3190709335dd31fe1aeeebfe4ffb6c7624ef971f upstream

This allows to load a different number of MSRs depending on the context:
VMEXIT or VMENTER.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Add find_msr() helper function
Konrad Rzeszutek Wilk [Thu, 21 Jun 2018 00:11:39 +0000 (20:11 -0400)]
x86/KVM/VMX: Add find_msr() helper function

commit ca83b4a7f2d068da79a029d323024aa45decb250 upstream

.. to help find the MSR on either the guest or host MSR list.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Split the VMX MSR LOAD structures to have an host/guest numbers
Konrad Rzeszutek Wilk [Wed, 20 Jun 2018 17:58:37 +0000 (13:58 -0400)]
x86/KVM/VMX: Split the VMX MSR LOAD structures to have an host/guest numbers

commit 33966dd6b2d2c352fae55412db2ea8cfff5df13a upstream

There is no semantic change but this change allows an unbalanced amount of
MSRs to be loaded on VMEXIT and VMENTER, i.e. the number of MSRs to save or
restore on VMEXIT or VMENTER may be different.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Add L1D flush logic
Paolo Bonzini [Mon, 2 Jul 2018 11:07:14 +0000 (13:07 +0200)]
x86/KVM/VMX: Add L1D flush logic

commit c595ceee45707f00f64f61c54fb64ef0cc0b4e85 upstream

Add the logic for flushing L1D on VMENTER. The flush depends on the static
key being enabled and the new l1tf_flush_l1d flag being set.

The flags is set:
 - Always, if the flush module parameter is 'always'

 - Conditionally at:
   - Entry to vcpu_run(), i.e. after executing user space

   - From the sched_in notifier, i.e. when switching to a vCPU thread.

   - From vmexit handlers which are considered unsafe, i.e. where
     sensitive data can be brought into L1D:

     - The emulator, which could be a good target for other speculative
       execution-based threats,

     - The MMU, which can bring host page tables in the L1 cache.

     - External interrupts

     - Nested operations that require the MMU (see above). That is
       vmptrld, vmptrst, vmclear,vmwrite,vmread.

     - When handling invept,invvpid

[ tglx: Split out from combo patch and reduced to a single flag ]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Add L1D MSR based flush
Paolo Bonzini [Mon, 2 Jul 2018 11:03:48 +0000 (13:03 +0200)]
x86/KVM/VMX: Add L1D MSR based flush

commit 3fa045be4c720146b18a19cea7a767dc6ad5df94 upstream

336996-Speculative-Execution-Side-Channel-Mitigations.pdf defines a new MSR
(IA32_FLUSH_CMD aka 0x10B) which has similar write-only semantics to other
MSRs defined in the document.

The semantics of this MSR is to allow "finer granularity invalidation of
caching structures than existing mechanisms like WBINVD. It will writeback
and invalidate the L1 data cache, including all cachelines brought in by
preceding instructions, without invalidating all caches (eg. L2 or
LLC). Some processors may also invalidate the first level level instruction
cache on a L1D_FLUSH command. The L1 data and instruction caches may be
shared across the logical processors of a core."

Use it instead of the loop based L1 flush algorithm.

A copy of this document is available at
   https://bugzilla.kernel.org/show_bug.cgi?id=199511

[ tglx: Avoid allocating pages when the MSR is available ]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Add L1D flush algorithm
Paolo Bonzini [Mon, 2 Jul 2018 10:47:38 +0000 (12:47 +0200)]
x86/KVM/VMX: Add L1D flush algorithm

commit a47dd5f06714c844b33f3b5f517b6f3e81ce57b5 upstream

To mitigate the L1 Terminal Fault vulnerability it's required to flush L1D
on VMENTER to prevent rogue guests from snooping host memory.

CPUs will have a new control MSR via a microcode update to flush L1D with a
single MSR write, but in the absence of microcode a fallback to a software
based flush algorithm is required.

Add a software flush loop which is based on code from Intel.

[ tglx: Split out from combo patch ]
[ bpetkov: Polish the asm code ]

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM/VMX: Add module argument for L1TF mitigation
Konrad Rzeszutek Wilk [Mon, 2 Jul 2018 10:29:30 +0000 (12:29 +0200)]
x86/KVM/VMX: Add module argument for L1TF mitigation

commit a399477e52c17e148746d3ce9a483f681c2aa9a0 upstream

Add a mitigation mode parameter "vmentry_l1d_flush" for CVE-2018-3620, aka
L1 terminal fault. The valid arguments are:

 - "always"  L1D cache flush on every VMENTER.
 - "cond" Conditional L1D cache flush, explained below
 - "never" Disable the L1D cache flush mitigation

"cond" is trying to avoid L1D cache flushes on VMENTER if the code executed
between VMEXIT and VMENTER is considered safe, i.e. is not bringing any
interesting information into L1D which might exploited.

[ tglx: Split out from a larger patch ]

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/KVM: Warn user if KVM is loaded SMT and L1TF CPU bug being present
Konrad Rzeszutek Wilk [Wed, 20 Jun 2018 15:29:53 +0000 (11:29 -0400)]
x86/KVM: Warn user if KVM is loaded SMT and L1TF CPU bug being present

commit 26acfb666a473d960f0fd971fe68f3e3ad16c70b upstream

If the L1TF CPU bug is present we allow the KVM module to be loaded as the
major of users that use Linux and KVM have trusted guests and do not want a
broken setup.

Cloud vendors are the ones that are uncomfortable with CVE 2018-3620 and as
such they are the ones that should set nosmt to one.

Setting 'nosmt' means that the system administrator also needs to disable
SMT (Hyper-threading) in the BIOS, or via the 'nosmt' command line
parameter, or via the /sys/devices/system/cpu/smt/control. See commit
05736e4ac13c ("cpu/hotplug: Provide knobs to control SMT").

Other mitigations are to use task affinity, cpu sets, interrupt binding,
etc - anything to make sure that _only_ the same guests vCPUs are running
on sibling threads.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agocpu/hotplug: Boot HT siblings at least once
Thomas Gleixner [Fri, 29 Jun 2018 14:05:48 +0000 (16:05 +0200)]
cpu/hotplug: Boot HT siblings at least once

commit 0cc3cd21657be04cb0559fe8063f2130493f92cf upstream

Due to the way Machine Check Exceptions work on X86 hyperthreads it's
required to boot up _all_ logical cores at least once in order to set the
CR4.MCE bit.

So instead of ignoring the sibling threads right away, let them boot up
once so they can configure themselves. After they came out of the initial
boot stage check whether its a "secondary" sibling and cancel the operation
which puts the CPU back into offline state.

Reported-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agoRevert "x86/apic: Ignore secondary threads if nosmt=force"
Thomas Gleixner [Fri, 29 Jun 2018 14:05:47 +0000 (16:05 +0200)]
Revert "x86/apic: Ignore secondary threads if nosmt=force"

commit 506a66f374891ff08e064a058c446b336c5ac760 upstream

Dave Hansen reported, that it's outright dangerous to keep SMT siblings
disabled completely so they are stuck in the BIOS and wait for SIPI.

The reason is that Machine Check Exceptions are broadcasted to siblings and
the soft disabled sibling has CR4.MCE = 0. If a MCE is delivered to a
logical core with CR4.MCE = 0, it asserts IERR#, which shuts down or
reboots the machine. The MCE chapter in the SDM contains the following
blurb:

    Because the logical processors within a physical package are tightly
    coupled with respect to shared hardware resources, both logical
    processors are notified of machine check errors that occur within a
    given physical processor. If machine-check exceptions are enabled when
    a fatal error is reported, all the logical processors within a physical
    package are dispatched to the machine-check exception handler. If
    machine-check exceptions are disabled, the logical processors enter the
    shutdown state and assert the IERR# signal. When enabling machine-check
    exceptions, the MCE flag in control register CR4 should be set for each
    logical processor.

Reverting the commit which ignores siblings at enumeration time solves only
half of the problem. The core cpuhotplug logic needs to be adjusted as
well.

This thoughtful engineered mechanism also turns the boot process on all
Intel HT enabled systems into a MCE lottery. MCE is enabled on the boot CPU
before the secondary CPUs are brought up. Depending on the number of
physical cores the window in which this situation can happen is smaller or
larger. On a HSW-EX it's about 750ms:

MCE is enabled on the boot CPU:

[    0.244017] mce: CPU supports 22 MCE banks

The corresponding sibling #72 boots:

[    1.008005] .... node  #0, CPUs:    #72

That means if an MCE hits on physical core 0 (logical CPUs 0 and 72)
between these two points the machine is going to shutdown. At least it's a
known safe state.

It's obvious that the early boot can be hit by an MCE as well and then runs
into the same situation because MCEs are not yet enabled on the boot CPU.
But after enabling them on the boot CPU, it does not make any sense to
prevent the kernel from recovering.

Adjust the nosmt kernel parameter documentation as well.

Reverts: 2207def700f9 ("x86/apic: Ignore secondary threads if nosmt=force")
Reported-by: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/speculation/l1tf: Fix up pte->pfn conversion for PAE
Michal Hocko [Wed, 27 Jun 2018 15:46:50 +0000 (17:46 +0200)]
x86/speculation/l1tf: Fix up pte->pfn conversion for PAE

commit e14d7dfb41f5807a0c1c26a13f2b8ef16af24935 upstream

Jan has noticed that pte_pfn and co. resp. pfn_pte are incorrect for
CONFIG_PAE because phys_addr_t is wider than unsigned long and so the
pte_val reps. shift left would get truncated. Fix this up by using proper
types.

Fixes: 6b28baca9b1f ("x86/speculation/l1tf: Protect PROT_NONE PTEs against speculation")
Reported-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/speculation/l1tf: Protect PAE swap entries against L1TF
Vlastimil Babka [Fri, 22 Jun 2018 15:39:33 +0000 (17:39 +0200)]
x86/speculation/l1tf: Protect PAE swap entries against L1TF

commit 0d0f6249058834ffe1ceaad0bb31464af66f6e7a upstream

The PAE 3-level paging code currently doesn't mitigate L1TF by flipping the
offset bits, and uses the high PTE word, thus bits 32-36 for type, 37-63 for
offset. The lower word is zeroed, thus systems with less than 4GB memory are
safe. With 4GB to 128GB the swap type selects the memory locations vulnerable
to L1TF; with even more memory, also the swap offfset influences the address.
This might be a problem with 32bit PAE guests running on large 64bit hosts.

By continuing to keep the whole swap entry in either high or low 32bit word of
PTE we would limit the swap size too much. Thus this patch uses the whole PAE
PTE with the same layout as the 64bit version does. The macros just become a
bit tricky since they assume the arch-dependent swp_entry_t to be 32bit.

Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/CPU/AMD: Move TOPOEXT reenablement before reading smp_num_siblings
Borislav Petkov [Fri, 22 Jun 2018 09:34:11 +0000 (11:34 +0200)]
x86/CPU/AMD: Move TOPOEXT reenablement before reading smp_num_siblings

commit 7ce2f0393ea2396142b7faf6ee9b1f3676d08a5f upstream

The TOPOEXT reenablement is a workaround for broken BIOSen which didn't
enable the CPUID bit. amd_get_topology_early(), however, relies on
that bit being set so that it can read out the CPUID leaf and set
smp_num_siblings properly.

Move the reenablement up to early_init_amd(). While at it, simplify
amd_get_topology_early().

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/cpufeatures: Add detection of L1D cache flush support.
Konrad Rzeszutek Wilk [Wed, 20 Jun 2018 20:42:58 +0000 (16:42 -0400)]
x86/cpufeatures: Add detection of L1D cache flush support.

commit 11e34e64e4103955fc4568750914c75d65ea87ee upstream

336996-Speculative-Execution-Side-Channel-Mitigations.pdf defines a new MSR
(IA32_FLUSH_CMD) which is detected by CPUID.7.EDX[28]=1 bit being set.

This new MSR "gives software a way to invalidate structures with finer
granularity than other architectual methods like WBINVD."

A copy of this document is available at
  https://bugzilla.kernel.org/show_bug.cgi?id=199511

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/speculation/l1tf: Extend 64bit swap file size limit
Vlastimil Babka [Thu, 21 Jun 2018 10:36:29 +0000 (12:36 +0200)]
x86/speculation/l1tf: Extend 64bit swap file size limit

commit 1a7ed1ba4bba6c075d5ad61bb75e3fbc870840d6 upstream

The previous patch has limited swap file size so that large offsets cannot
clear bits above MAX_PA/2 in the pte and interfere with L1TF mitigation.

It assumed that offsets are encoded starting with bit 12, same as pfn. But
on x86_64, offsets are encoded starting with bit 9.

Thus the limit can be raised by 3 bits. That means 16TB with 42bit MAX_PA
and 256TB with 46bit MAX_PA.

Fixes: 377eeaa8e11f ("x86/speculation/l1tf: Limit swap file size to MAX_PA/2")
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/apic: Ignore secondary threads if nosmt=force
Thomas Gleixner [Tue, 5 Jun 2018 12:00:11 +0000 (14:00 +0200)]
x86/apic: Ignore secondary threads if nosmt=force

commit 2207def700f902f169fc237b717252c326f9e464 upstream

nosmt on the kernel command line merely prevents the onlining of the
secondary SMT siblings.

nosmt=force makes the APIC detection code ignore the secondary SMT siblings
completely, so they even do not show up as possible CPUs. That reduces the
amount of memory allocations for per cpu variables and saves other
resources from being allocated too large.

This is not fully equivalent to disabling SMT in the BIOS because the low
level SMT enabling in the BIOS can result in partitioning of resources
between the siblings, which is not undone by just ignoring them. Some CPUs
can use the full resources when their sibling is not onlined, but this is
depending on the CPU family and model and it's not well documented whether
this applies to all partitioned resources. That means depending on the
workload disabling SMT in the BIOS might result in better performance.

Linus analysis of the Intel manual:

  The intel optimization manual is not very clear on what the partitioning
  rules are.

  I find:

    "In general, the buffers for staging instructions between major pipe
     stages  are partitioned. These buffers include µop queues after the
     execution trace cache, the queues after the register rename stage, the
     reorder buffer which stages instructions for retirement, and the load
     and store buffers.

     In the case of load and store buffers, partitioning also provided an
     easier implementation to maintain memory ordering for each logical
     processor and detect memory ordering violations"

  but some of that partitioning may be relaxed if the HT thread is "not
  active":

    "In Intel microarchitecture code name Sandy Bridge, the micro-op queue
     is statically partitioned to provide 28 entries for each logical
     processor,  irrespective of software executing in single thread or
     multiple threads. If one logical processor is not active in Intel
     microarchitecture code name Ivy Bridge, then a single thread executing
     on that processor  core can use the 56 entries in the micro-op queue"

  but I do not know what "not active" means, and how dynamic it is. Some of
  that partitioning may be entirely static and depend on the early BIOS
  disabling of HT, and even if we park the cores, the resources will just be
  wasted.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/cpu/AMD: Evaluate smp_num_siblings early
Thomas Gleixner [Tue, 5 Jun 2018 22:57:38 +0000 (00:57 +0200)]
x86/cpu/AMD: Evaluate smp_num_siblings early

commit 1e1d7e25fd759eddf96d8ab39d0a90a1979b2d8c upstream

To support force disabling of SMT it's required to know the number of
thread siblings early. amd_get_topology() cannot be called before the APIC
driver is selected, so split out the part which initializes
smp_num_siblings and invoke it from amd_early_init().

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/CPU/AMD: Do not check CPUID max ext level before parsing SMP info
Borislav Petkov [Fri, 15 Jun 2018 18:48:39 +0000 (20:48 +0200)]
x86/CPU/AMD: Do not check CPUID max ext level before parsing SMP info

commit 119bff8a9c9bb00116a844ec68be7bc4b1c768f5 upstream

Old code used to check whether CPUID ext max level is >= 0x80000008 because
that last leaf contains the number of cores of the physical CPU.  The three
functions called there now do not depend on that leaf anymore so the check
can go.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
6 years agox86/cpu/intel: Evaluate smp_num_siblings early
Thomas Gleixner [Tue, 5 Jun 2018 23:00:55 +0000 (01:00 +0200)]
x86/cpu/intel: Evaluate smp_num_siblings early

commit 1910ad5624968f93be48e8e265513c54d66b897c upstream

Make use of the new early detection function to initialize smp_num_siblings
on the boot cpu before the MP-Table or ACPI/MADT scan happens. That's
required for force disabling SMT.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>