From ea8ffc0818d8a47ffda423f61f1d8ad1caca8986 Mon Sep 17 00:00:00 2001 From: Mahesh Bandewar Date: Thu, 20 Apr 2017 12:49:24 -0700 Subject: [PATCH] bonding: fix wq initialization for links created via netlink Earlier patch 4493b81bea ("bonding: initialize work-queues during creation of bond") moved the work-queue initialization from bond_open() to bond_create(). However this caused the link those are created using netlink 'create bond option' (ip link add bondX type bond); create the new trunk without initializing work-queues. Prior to the above mentioned change, ndo_open was in both paths and things worked correctly. The consequence is visible in the report shared by Joe Stringer - I've noticed that this patch breaks bonding within namespaces if you're not careful to perform device cleanup correctly. Here's my repro script, you can run on any net-next with this patch and you'll start seeing some weird behaviour: ip netns add foo ip li add veth0 type veth peer name veth0+ netns foo ip li add veth1 type veth peer name veth1+ netns foo ip netns exec foo ip li add bond0 type bond ip netns exec foo ip li set dev veth0+ master bond0 ip netns exec foo ip li set dev veth1+ master bond0 ip netns exec foo ip addr add dev bond0 192.168.0.1/24 ip netns exec foo ip li set dev bond0 up ip li del dev veth0 ip li del dev veth1 The second to last command segfaults, last command hangs. rtnl is now permanently locked. It's not a problem if you take bond0 down before deleting veths, or delete bond0 before deleting veths. If you delete either end of the veth pair as per above, either inside or outside the namespace, it hits this problem. Here's some kernel logs: [ 1221.801610] bond0: Enslaving veth0+ as an active interface with an up link [ 1224.449581] bond0: Enslaving veth1+ as an active interface with an up link [ 1281.193863] bond0: Releasing backup interface veth0+ [ 1281.193866] bond0: the permanent HWaddr of veth0+ - 16:bf:fb:e0:b8:43 - is still in use by bond0 - set the HWaddr of veth0+ to a different address to avoid conflicts [ 1281.193867] ------------[ cut here ]------------ [ 1281.193873] WARNING: CPU: 0 PID: 2024 at kernel/workqueue.c:1511 __queue_delayed_work+0x13f/0x150 [ 1281.193873] Modules linked in: bonding veth openvswitch nf_nat_ipv6 nf_nat_ipv4 nf_nat autofs4 nfsd auth_rpcgss nfs_acl binfmt_misc nfs lockd grace sunrpc fscache ppdev vmw_balloon coretemp psmouse serio_raw vmwgfx ttm drm_kms_helper vmw_vmci netconsole parport_pc configfs drm i2c_piix4 fb_sys_fops syscopyarea sysfillrect sysimgblt shpchp mac_hid nf_conntrack_ipv6 nf_defrag_ipv6 nf_conntrack_ipv4 nf_defrag_ipv4 nf_conntrack libcrc32c lp parport hid_generic usbhid hid mptspi mptscsih e1000 mptbase ahci libahci [ 1281.193905] CPU: 0 PID: 2024 Comm: ip Tainted: G W 4.10.0-bisect-bond-v0.14 #37 [ 1281.193906] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/30/2014 [ 1281.193906] Call Trace: [ 1281.193912] dump_stack+0x63/0x89 [ 1281.193915] __warn+0xd1/0xf0 [ 1281.193917] warn_slowpath_null+0x1d/0x20 [ 1281.193918] __queue_delayed_work+0x13f/0x150 [ 1281.193920] queue_delayed_work_on+0x27/0x40 [ 1281.193929] bond_change_active_slave+0x25b/0x670 [bonding] [ 1281.193932] ? synchronize_rcu_expedited+0x27/0x30 [ 1281.193935] __bond_release_one+0x489/0x510 [bonding] [ 1281.193939] ? addrconf_notify+0x1b7/0xab0 [ 1281.193942] bond_netdev_event+0x2c5/0x2e0 [bonding] [ 1281.193944] ? netconsole_netdev_event+0x124/0x190 [netconsole] [ 1281.193947] notifier_call_chain+0x49/0x70 [ 1281.193948] raw_notifier_call_chain+0x16/0x20 [ 1281.193950] call_netdevice_notifiers_info+0x35/0x60 [ 1281.193951] rollback_registered_many+0x23b/0x3e0 [ 1281.193953] unregister_netdevice_many+0x24/0xd0 [ 1281.193955] rtnl_delete_link+0x3c/0x50 [ 1281.193956] rtnl_dellink+0x8d/0x1b0 [ 1281.193960] rtnetlink_rcv_msg+0x95/0x220 [ 1281.193962] ? __kmalloc_node_track_caller+0x35/0x280 [ 1281.193964] ? __netlink_lookup+0xf1/0x110 [ 1281.193966] ? rtnl_newlink+0x830/0x830 [ 1281.193967] netlink_rcv_skb+0xa7/0xc0 [ 1281.193969] rtnetlink_rcv+0x28/0x30 [ 1281.193970] netlink_unicast+0x15b/0x210 [ 1281.193971] netlink_sendmsg+0x319/0x390 [ 1281.193974] sock_sendmsg+0x38/0x50 [ 1281.193975] ___sys_sendmsg+0x25c/0x270 [ 1281.193978] ? mem_cgroup_commit_charge+0x76/0xf0 [ 1281.193981] ? page_add_new_anon_rmap+0x89/0xc0 [ 1281.193984] ? lru_cache_add_active_or_unevictable+0x35/0xb0 [ 1281.193985] ? __handle_mm_fault+0x4e9/0x1170 [ 1281.193987] __sys_sendmsg+0x45/0x80 [ 1281.193989] SyS_sendmsg+0x12/0x20 [ 1281.193991] do_syscall_64+0x6e/0x180 [ 1281.193993] entry_SYSCALL64_slow_path+0x25/0x25 [ 1281.193995] RIP: 0033:0x7f6ec122f5a0 [ 1281.193995] RSP: 002b:00007ffe69e89c48 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 1281.193997] RAX: ffffffffffffffda RBX: 00007ffe69e8dd60 RCX: 00007f6ec122f5a0 [ 1281.193997] RDX: 0000000000000000 RSI: 00007ffe69e89c90 RDI: 0000000000000003 [ 1281.193998] RBP: 00007ffe69e89c90 R08: 0000000000000000 R09: 0000000000000003 [ 1281.193999] R10: 00007ffe69e89a10 R11: 0000000000000246 R12: 0000000058f14b9f [ 1281.193999] R13: 0000000000000000 R14: 00000000006473a0 R15: 00007ffe69e8e450 [ 1281.194001] ---[ end trace 713a77486cbfbfa3 ]--- Fixes: 4493b81bea ("bonding: initialize work-queues during creation of bond") Reported-by: Joe Stringer Tested-by: Joe Stringer Signed-off-by: Mahesh Bandewar Acked-by: Andy Gospodarek Signed-off-by: David S. Miller --- drivers/net/bonding/bond_main.c | 2 +- drivers/net/bonding/bond_netlink.c | 5 +++++ include/net/bonding.h | 1 + 3 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 6bd3b50faf48..e549bf6f5cac 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3243,7 +3243,7 @@ u32 bond_xmit_hash(struct bonding *bond, struct sk_buff *skb) /*-------------------------- Device entry points ----------------------------*/ -static void bond_work_init_all(struct bonding *bond) +void bond_work_init_all(struct bonding *bond) { INIT_DELAYED_WORK(&bond->mcast_work, bond_resend_igmp_join_requests_delayed); diff --git a/drivers/net/bonding/bond_netlink.c b/drivers/net/bonding/bond_netlink.c index b8df0f5e8c25..c502c139d3bc 100644 --- a/drivers/net/bonding/bond_netlink.c +++ b/drivers/net/bonding/bond_netlink.c @@ -449,6 +449,11 @@ static int bond_newlink(struct net *src_net, struct net_device *bond_dev, err = register_netdevice(bond_dev); netif_carrier_off(bond_dev); + if (!err) { + struct bonding *bond = netdev_priv(bond_dev); + + bond_work_init_all(bond); + } return err; } diff --git a/include/net/bonding.h b/include/net/bonding.h index 04a21e8048be..b00508d22e0a 100644 --- a/include/net/bonding.h +++ b/include/net/bonding.h @@ -614,6 +614,7 @@ struct bond_vlan_tag *bond_verify_device_path(struct net_device *start_dev, int level); int bond_update_slave_arr(struct bonding *bond, struct slave *skipslave); void bond_slave_arr_work_rearm(struct bonding *bond, unsigned long delay); +void bond_work_init_all(struct bonding *bond); #ifdef CONFIG_PROC_FS void bond_create_proc_entry(struct bonding *bond); -- 2.20.1