syzbot


INFO: task hung in tipc_exit_net

Status: auto-closed as invalid on 2021/09/06 01:04
Reported-by: syzbot+1a73b0bb8628407f0907@syzkaller.appspotmail.com
First crash: 590d, last: 504d
similar bugs (3):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 INFO: task hung in tipc_exit_net (2) 2 279d 293d 0/1 auto-closed as invalid on 2022/04/19 05:05
linux-4.19 INFO: task hung in tipc_exit_net C 285 6h20m 674d 0/1 upstream: reported C repro on 2020/11/20 02:47
upstream INFO: task hung in tipc_exit_net 2 750d 753d 0/24 auto-closed as invalid on 2020/12/03 19:41

Sample crash report:
Bluetooth: hci0 command 0x0419 tx timeout
Bluetooth: hci0 command 0x0409 tx timeout
Bluetooth: hci0 command 0x041b tx timeout
Bluetooth: hci0 command 0x040f tx timeout
Bluetooth: hci0 command 0x0419 tx timeout
INFO: task kworker/u4:5:9257 blocked for more than 140 seconds.
      Not tainted 4.14.232-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:5    D27040  9257      2 0x80000000
Workqueue: netns cleanup_net
Call Trace:
 context_switch kernel/sched/core.c:2808 [inline]
 __schedule+0x88b/0x1de0 kernel/sched/core.c:3384
 schedule+0x8d/0x1b0 kernel/sched/core.c:3428
 schedule_timeout+0x80a/0xe90 kernel/time/timer.c:1724
 do_wait_for_common kernel/sched/completion.c:91 [inline]
 __wait_for_common kernel/sched/completion.c:112 [inline]
 wait_for_common+0x272/0x430 kernel/sched/completion.c:123
 flush_workqueue+0x3ce/0x1310 kernel/workqueue.c:2676
 flush_scheduled_work include/linux/workqueue.h:578 [inline]
 tipc_exit_net+0x38/0x60 net/tipc/core.c:96
 ops_exit_list+0xa5/0x150 net/core/net_namespace.c:142
 cleanup_net+0x3b3/0x840 net/core/net_namespace.c:484
 process_one_work+0x793/0x14a0 kernel/workqueue.c:2116
 worker_thread+0x5cc/0xff0 kernel/workqueue.c:2250
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404

Showing all locks held in the system:
3 locks held by kworker/0:0/3:
 #0:  ("events"){+.+.}, at: [<ffffffff813639b0>] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087
 #1:  ((&smc->tcp_listen_work)){+.+.}, at: [<ffffffff813639e6>] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091
 #2:  (&smc->clcsock_release_lock){+.+.}, at: [<ffffffff86d2f3dc>] smc_clcsock_accept net/smc/af_smc.c:600 [inline]
 #2:  (&smc->clcsock_release_lock){+.+.}, at: [<ffffffff86d2f3dc>] smc_tcp_listen_work+0x6ac/0xb80 net/smc/af_smc.c:935
3 locks held by kworker/1:1/23:
 #0:  ("events"){+.+.}, at: [<ffffffff813639b0>] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087
 #1:  ((&smc->tcp_listen_work)){+.+.}, at: [<ffffffff813639e6>] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091
 #2:  (&smc->clcsock_release_lock){+.+.}, at: [<ffffffff86d2f3dc>] smc_clcsock_accept net/smc/af_smc.c:600 [inline]
 #2:  (&smc->clcsock_release_lock){+.+.}, at: [<ffffffff86d2f3dc>] smc_tcp_listen_work+0x6ac/0xb80 net/smc/af_smc.c:935
1 lock held by khungtaskd/1533:
 #0:  (tasklist_lock){.+.+}, at: [<ffffffff8700b7b7>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4548
3 locks held by kworker/1:2/3625:
 #0:  ("events"){+.+.}, at: [<ffffffff813639b0>] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087
 #1:  ((&smc->tcp_listen_work)){+.+.}, at: [<ffffffff813639e6>] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091
 #2:  (&smc->clcsock_release_lock){+.+.}, at: [<ffffffff86d2f3dc>] smc_clcsock_accept net/smc/af_smc.c:600 [inline]
 #2:  (&smc->clcsock_release_lock){+.+.}, at: [<ffffffff86d2f3dc>] smc_tcp_listen_work+0x6ac/0xb80 net/smc/af_smc.c:935
1 lock held by in:imklog/7676:
 #0:  (&f->f_pos_lock){+.+.}, at: [<ffffffff818d39ab>] __fdget_pos+0x1fb/0x2b0 fs/file.c:769
3 locks held by kworker/u4:5/9257:
 #0:  ("%s""netns"){+.+.}, at: [<ffffffff813639b0>] process_one_work+0x6b0/0x14a0 kernel/workqueue.c:2087
 #1:  (net_cleanup_work){+.+.}, at: [<ffffffff813639e6>] process_one_work+0x6e6/0x14a0 kernel/workqueue.c:2091
 #2:  (net_mutex){+.+.}, at: [<ffffffff85c0eb70>] cleanup_net+0x110/0x840 net/core/net_namespace.c:450
1 lock held by syz-executor.1/12015:
 #0:  (net_mutex){+.+.}, at: [<ffffffff85c0f3f6>] copy_net_ns+0x156/0x440 net/core/net_namespace.c:410

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 1533 Comm: khungtaskd Not tainted 4.14.232-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x281 lib/dump_stack.c:58
 nmi_cpu_backtrace.cold+0x57/0x93 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x13a/0x180 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:140 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline]
 watchdog+0x5b9/0xb40 kernel/hung_task.c:274
 kthread+0x30d/0x420 kernel/kthread.c:232
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4618 Comm: systemd-journal Not tainted 4.14.232-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880a146a6c0 task.stack: ffff8880a1470000
RIP: 0010:__sanitizer_cov_trace_pc+0x9/0x50 kernel/kcov.c:65
RSP: 0018:ffff8880a1477ca0 EFLAGS: 00000046
RAX: ffff8880a146a6c0 RBX: 0000000000000000 RCX: 00000000000003ef
RDX: 1ffff1101428dbcd RSI: 0000000000000001 RDI: ffff8880a146dd04
RBP: ffff8880a146dd00 R08: ffffffff8b991a38 R09: 00000000000c0471
R10: ffff8880a146af70 R11: ffff8880a146a6c0 R12: ffff8880a1477e20
R13: ffff8880a146de48 R14: ffff8880a1477d00 R15: 0000000000000286
FS:  00007f99bc6e48c0(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f99b9b91000 CR3: 00000000a1651000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ep_scan_ready_list+0x37a/0x7e0 fs/eventpoll.c:737
 ep_send_events fs/eventpoll.c:1723 [inline]
 ep_poll+0x234/0xa50 fs/eventpoll.c:1848
 SYSC_epoll_wait fs/eventpoll.c:2195 [inline]
 SyS_epoll_wait+0x150/0x1a0 fs/eventpoll.c:2160
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f99bb9ad2e3
RSP: 002b:00007ffe812d87b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 000055c08234d1e0 RCX: 00007f99bb9ad2e3
RDX: 0000000000000013 RSI: 00007ffe812d87c0 RDI: 0000000000000008
RBP: 00007ffe812d89b0 R08: 00007ffe81384000 R09: 000000743a12b464
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe812d87c0
R13: 0000000000000001 R14: ffffffffffffffff R15: 0005c1db3c55850c
Code: 00 e9 9f fe ff ff 4c 89 e7 e8 44 a5 29 00 e9 2c fe ff ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 04 25 80 df 01 00 <48> 85 c0 74 1a 65 8b 15 8b b9 ac 7e 81 e2 00 01 1f 00 75 0b 8b 

Crashes (8):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-14 2021/05/09 01:04 linux-4.14.y 7d7d1c0ab3eb bc5434be .config log report info INFO: task hung in tipc_exit_net
ci2-linux-4-14 2021/04/24 03:19 linux-4.14.y cf256fbcbe34 17f0b706 .config log report info INFO: task hung in tipc_exit_net
ci2-linux-4-14 2021/04/22 18:55 linux-4.14.y cf256fbcbe34 33c28d03 .config log report info INFO: task hung in tipc_exit_net
ci2-linux-4-14 2021/04/17 02:23 linux-4.14.y cf256fbcbe34 7e2b734b .config log report info INFO: task hung in tipc_exit_net
ci2-linux-4-14 2021/04/08 03:16 linux-4.14.y 0cc244011f40 6a81331a .config log report info INFO: task hung in tipc_exit_net
ci2-linux-4-14 2021/03/22 17:40 linux-4.14.y cb83ddcd5332 bea32f74 .config log report info INFO: task hung in tipc_exit_net
ci2-linux-4-14 2021/03/05 21:51 linux-4.14.y 397a88b2cc86 4a024a9b .config log report info INFO: task hung in tipc_exit_net
ci2-linux-4-14 2021/02/11 22:56 linux-4.14.y 2c8a3fceddf0 a5f86b15 .config log report info INFO: task hung in tipc_exit_net
* Struck through repros no longer work on HEAD.