syzbot


possible deadlock in start_sync_thread

Status: upstream: reported on 2024/06/24 15:27
Subsystems: lvs
[Documentation on labels]
Reported-by: syzbot+e929093395ec65f969c7@syzkaller.appspotmail.com
First crash: 26d, last: 4d19h
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [lvs?] possible deadlock in start_sync_thread 0 (1) 2024/06/24 15:27
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 possible deadlock in start_sync_thread C 9 2214d 1923d 0/3 public: reported C repro on 2019/04/14 00:00

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc7-syzkaller-01794-g8e5f53a68433 #0 Not tainted
------------------------------------------------------
syz.0.2054/11811 is trying to acquire lock:
ffffffff8f5ec9c8 (rtnl_mutex){+.+.}-{3:3}, at: start_sync_thread+0xdc/0x2dc0 net/netfilter/ipvs/ip_vs_sync.c:1761

but task is already holding lock:
ffff88802e225750 (&smc->clcsock_release_lock){+.+.}-{3:3}, at: smc_setsockopt+0x1c3/0xe50 net/smc/af_smc.c:3064

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&smc->clcsock_release_lock){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       smc_switch_to_fallback+0x35/0xd00 net/smc/af_smc.c:902
       smc_sendmsg+0x11f/0x530 net/smc/af_smc.c:2779
       sock_sendmsg_nosec net/socket.c:730 [inline]
       __sock_sendmsg+0x221/0x270 net/socket.c:745
       __sys_sendto+0x3a4/0x4f0 net/socket.c:2192
       __do_sys_sendto net/socket.c:2204 [inline]
       __se_sys_sendto net/socket.c:2200 [inline]
       __x64_sys_sendto+0xde/0x100 net/socket.c:2200
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (sk_lock-AF_INET){+.+.}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       lock_sock_nested+0x48/0x100 net/core/sock.c:3543
       do_ip_setsockopt+0x1a2d/0x3cd0 net/ipv4/ip_sockglue.c:1078
       ip_setsockopt+0x63/0x100 net/ipv4/ip_sockglue.c:1417
       do_sock_setsockopt+0x3af/0x720 net/socket.c:2312
       __sys_setsockopt+0x1ae/0x250 net/socket.c:2335
       __do_sys_setsockopt net/socket.c:2344 [inline]
       __se_sys_setsockopt net/socket.c:2341 [inline]
       __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2341
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (rtnl_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3869
       __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
       start_sync_thread+0xdc/0x2dc0 net/netfilter/ipvs/ip_vs_sync.c:1761
       do_ip_vs_set_ctl+0x442/0x13d0 net/netfilter/ipvs/ip_vs_ctl.c:2732
       nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101
       smc_setsockopt+0x275/0xe50 net/smc/af_smc.c:3072
       do_sock_setsockopt+0x3af/0x720 net/socket.c:2312
       __sys_setsockopt+0x1ae/0x250 net/socket.c:2335
       __do_sys_setsockopt net/socket.c:2344 [inline]
       __se_sys_setsockopt net/socket.c:2341 [inline]
       __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2341
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  rtnl_mutex --> sk_lock-AF_INET --> &smc->clcsock_release_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&smc->clcsock_release_lock);
                               lock(sk_lock-AF_INET);
                               lock(&smc->clcsock_release_lock);
  lock(rtnl_mutex);

 *** DEADLOCK ***

1 lock held by syz.0.2054/11811:
 #0: ffff88802e225750 (&smc->clcsock_release_lock){+.+.}-{3:3}, at: smc_setsockopt+0x1c3/0xe50 net/smc/af_smc.c:3064

stack backtrace:
CPU: 1 PID: 11811 Comm: syz.0.2054 Not tainted 6.10.0-rc7-syzkaller-01794-g8e5f53a68433 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3869
 __lock_acquire+0x1346/0x1fd0 kernel/locking/lockdep.c:5137
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
 __mutex_lock_common kernel/locking/mutex.c:608 [inline]
 __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752
 start_sync_thread+0xdc/0x2dc0 net/netfilter/ipvs/ip_vs_sync.c:1761
 do_ip_vs_set_ctl+0x442/0x13d0 net/netfilter/ipvs/ip_vs_ctl.c:2732
 nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101
 smc_setsockopt+0x275/0xe50 net/smc/af_smc.c:3072
 do_sock_setsockopt+0x3af/0x720 net/socket.c:2312
 __sys_setsockopt+0x1ae/0x250 net/socket.c:2335
 __do_sys_setsockopt net/socket.c:2344 [inline]
 __se_sys_setsockopt net/socket.c:2341 [inline]
 __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2341
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6a2bd75bd9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6a2cac2048 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f6a2bf03f60 RCX: 00007f6a2bd75bd9
RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000009
RBP: 00007f6a2bde4e60 R08: 0000000000000018 R09: 0000000000000000
R10: 0000000020000200 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f6a2bf03f60 R15: 00007ffea80bfe68
 </TASK>
netlink: 60 bytes leftover after parsing attributes in process `syz.0.2054'.

Crashes (33):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/07/14 11:29 net-next 8e5f53a68433 eaeb5c15 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/09 00:02 net-next 3abbd7ed8b76 cde64f7d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/08 20:06 net-next 3abbd7ed8b76 cde64f7d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/08 18:47 net-next 3abbd7ed8b76 cde64f7d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/08 17:21 net-next 3abbd7ed8b76 cde64f7d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/08 07:26 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/08 07:17 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/08 04:08 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/08 03:50 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/08 03:12 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/08 02:39 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/08 02:36 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/08 00:18 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/07 21:32 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/07 16:29 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/07 15:01 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/07 13:44 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/07 13:30 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/07 08:46 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/07 08:03 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/07 07:34 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/07 04:04 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/07 00:52 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/06 19:20 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/06 16:34 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/06 12:09 net-next 2f5e6395714d bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/06 04:25 net-next c7f79f2620b7 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/06 04:16 net-next c7f79f2620b7 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/04 02:35 net-next cda91d5b911a 409d975c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/06/26 11:44 net-next 50b70845fc5c dec8bc94 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/06/25 19:23 net-next 73cfd947dbdb da0bd5ca .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/06/22 09:18 net-next 3226607302ca edc5149a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce possible deadlock in start_sync_thread
2024/07/06 21:01 linux-next 0b58e108042b bc4ebbb5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root possible deadlock in start_sync_thread
* Struck through repros no longer work on HEAD.