From 0972ddb2373d5e127aabdcabd8305eff0242cd0b Mon Sep 17 00:00:00 2001 From: Held Bernhard Date: Sun, 24 Apr 2011 22:07:32 +0000 Subject: [PATCH] net: provide cow_metrics() methods to blackhole dst_ops Since commit 62fa8a846d7d (net: Implement read-only protection and COW'ing of metrics.) the kernel throws an oops. [ 101.620985] BUG: unable to handle kernel NULL pointer dereference at (null) [ 101.621050] IP: [< (null)>] (null) [ 101.621084] PGD 6e53c067 PUD 3dd6a067 PMD 0 [ 101.621122] Oops: 0010 [#1] SMP [ 101.621153] last sysfs file: /sys/devices/virtual/ppp/ppp/uevent [ 101.621192] CPU 2 [ 101.621206] Modules linked in: l2tp_ppp pppox ppp_generic slhc l2tp_netlink l2tp_core deflate zlib_deflate twofish_x86_64 twofish_common des_generic cbc ecb sha1_generic hmac af_key iptable_filter snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device loop snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec snd_pcm snd_timer snd i2c_i801 iTCO_wdt psmouse soundcore snd_page_alloc evdev uhci_hcd ehci_hcd thermal [ 101.621552] [ 101.621567] Pid: 5129, comm: openl2tpd Not tainted 2.6.39-rc4-Quad #3 Gigabyte Technology Co., Ltd. G33-DS3R/G33-DS3R [ 101.621637] RIP: 0010:[<0000000000000000>] [< (null)>] (null) [ 101.621684] RSP: 0018:ffff88003ddeba60 EFLAGS: 00010202 [ 101.621716] RAX: ffff88003ddb5600 RBX: ffff88003ddb5600 RCX: 0000000000000020 [ 101.621758] RDX: ffffffff81a69a00 RSI: ffffffff81b7ee61 RDI: ffff88003ddb5600 [ 101.621800] RBP: ffff8800537cd900 R08: 0000000000000000 R09: ffff88003ddb5600 [ 101.621840] R10: 0000000000000005 R11: 0000000000014b38 R12: ffff88003ddb5600 [ 101.621881] R13: ffffffff81b7e480 R14: ffffffff81b7e8b8 R15: ffff88003ddebad8 [ 101.621924] FS: 00007f06e4182700(0000) GS:ffff88007fd00000(0000) knlGS:0000000000000000 [ 101.621971] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 101.622005] CR2: 0000000000000000 CR3: 0000000045274000 CR4: 00000000000006e0 [ 101.622046] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 101.622087] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 101.622129] Process openl2tpd (pid: 5129, threadinfo ffff88003ddea000, task ffff88003de9a280) [ 101.622177] Stack: [ 101.622191] ffffffff81447efa ffff88007d3ded80 ffff88003de9a280 ffff88007d3ded80 [ 101.622245] 0000000000000001 ffff88003ddebbb8 ffffffff8148d5a7 0000000000000212 [ 101.622299] ffff88003dcea000 ffff88003dcea188 ffffffff00000001 ffffffff81b7e480 [ 101.622353] Call Trace: [ 101.622374] [] ? ipv4_blackhole_route+0x1ba/0x210 [ 101.622415] [] ? xfrm_lookup+0x417/0x510 [ 101.622450] [] ? extract_buf+0x9a/0x140 [ 101.622485] [] ? __ip_flush_pending_frames+0x70/0x70 [ 101.622526] [] ? udp_sendmsg+0x62f/0x810 [ 101.622562] [] ? sock_sendmsg+0x116/0x130 [ 101.622599] [] ? find_get_page+0x18/0x90 [ 101.622633] [] ? filemap_fault+0x12a/0x4b0 [ 101.622668] [] ? move_addr_to_kernel+0x64/0x90 [ 101.622706] [] ? verify_iovec+0x7a/0xf0 [ 101.622739] [] ? sys_sendmsg+0x292/0x420 [ 101.622774] [] ? handle_pte_fault+0x8a/0x7c0 [ 101.622810] [] ? __pte_alloc+0xae/0x130 [ 101.622844] [] ? handle_mm_fault+0x138/0x380 [ 101.622880] [] ? do_page_fault+0x189/0x410 [ 101.622915] [] ? sys_getsockname+0xf3/0x110 [ 101.622952] [] ? ip_setsockopt+0x4d/0xa0 [ 101.622986] [] ? sockfd_lookup_light+0x22/0x90 [ 101.623024] [] ? system_call_fastpath+0x16/0x1b [ 101.623060] Code: Bad RIP value. [ 101.623090] RIP [< (null)>] (null) [ 101.623125] RSP [ 101.623146] CR2: 0000000000000000 [ 101.650871] ---[ end trace ca3856a7d8e8dad4 ]--- [ 101.651011] __sk_free: optmem leakage (160 bytes) detected. The oops happens in dst_metrics_write_ptr() include/net/dst.h:124: return dst->ops->cow_metrics(dst, p); dst->ops->cow_metrics is NULL and causes the oops. Provide cow_metrics() methods, like we did in commit 214f45c91bb (net: provide default_advmss() methods to blackhole dst_ops) Signed-off-by: Held Bernhard Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/route.c | 7 +++++++ net/ipv6/route.c | 7 +++++++ 2 files changed, 14 insertions(+) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index c1acf69858fd..99e6e4bb1c72 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -2690,6 +2690,12 @@ static void ipv4_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) { } +static u32 *ipv4_rt_blackhole_cow_metrics(struct dst_entry *dst, + unsigned long old) +{ + return NULL; +} + static struct dst_ops ipv4_dst_blackhole_ops = { .family = AF_INET, .protocol = cpu_to_be16(ETH_P_IP), @@ -2698,6 +2704,7 @@ static struct dst_ops ipv4_dst_blackhole_ops = { .default_mtu = ipv4_blackhole_default_mtu, .default_advmss = ipv4_default_advmss, .update_pmtu = ipv4_rt_blackhole_update_pmtu, + .cow_metrics = ipv4_rt_blackhole_cow_metrics, }; struct dst_entry *ipv4_blackhole_route(struct net *net, struct dst_entry *dst_orig) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 0a5d02ae5ceb..fd0eec6f88c6 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -153,6 +153,12 @@ static void ip6_rt_blackhole_update_pmtu(struct dst_entry *dst, u32 mtu) { } +static u32 *ip6_rt_blackhole_cow_metrics(struct dst_entry *dst, + unsigned long old) +{ + return NULL; +} + static struct dst_ops ip6_dst_blackhole_ops = { .family = AF_INET6, .protocol = cpu_to_be16(ETH_P_IPV6), @@ -161,6 +167,7 @@ static struct dst_ops ip6_dst_blackhole_ops = { .default_mtu = ip6_blackhole_default_mtu, .default_advmss = ip6_default_advmss, .update_pmtu = ip6_rt_blackhole_update_pmtu, + .cow_metrics = ip6_rt_blackhole_cow_metrics, }; static const u32 ip6_template_metrics[RTAX_MAX] = { -- 2.20.1