syzbot


INFO: task hung in fsnotify_connector_destroy_workfn (2)

Status: auto-closed as invalid on 2020/09/02 10:35
Reported-by: syzbot+6475953811358f45faab@syzkaller.appspotmail.com
First crash: 1022d, last: 1004d
similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in fsnotify_connector_destroy_workfn 1 1383d 1383d 0/1 auto-closed as invalid on 2019/10/19 09:18
android-414 INFO: task hung in fsnotify_connector_destroy_workfn 6 1172d 1391d 0/1 auto-closed as invalid on 2020/03/18 16:55
upstream INFO: task hung in fsnotify_connector_destroy_workfn syz 7 1656d 1735d 0/24 closed as dup on 2018/07/18 14:05
upstream INFO: task hung in fsnotify_connector_destroy_workfn (2) syz error error 62 969d 1602d 0/24 auto-obsoleted due to no activity on 2022/09/20 11:34

Sample crash report:
overlayfs: upperdir is in-use as upperdir/workdir of another mount, mount with '-o index=off' to override exclusive upperdir protection.
NOHZ: local_softirq_pending 08
INFO: task kworker/u4:5:7718 blocked for more than 140 seconds.
      Not tainted 4.19.120-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:5    D26208  7718      2 0x80000000
Workqueue: events_unbound fsnotify_connector_destroy_workfn
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_timeout+0x896/0xf20 kernel/time/timer.c:1782
 do_wait_for_common kernel/sched/completion.c:83 [inline]
 __wait_for_common kernel/sched/completion.c:104 [inline]
 wait_for_common kernel/sched/completion.c:115 [inline]
 wait_for_completion+0x26a/0x3c0 kernel/sched/completion.c:136
 __synchronize_srcu+0x12e/0x210 kernel/rcu/srcutree.c:936
 fsnotify_connector_destroy_workfn+0x49/0xa0 fs/notify/mark.c:174
 process_one_work+0x91f/0x1640 kernel/workqueue.c:2155
 worker_thread+0x96/0xe20 kernel/workqueue.c:2298
 kthread+0x34a/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task kworker/u4:6:7757 blocked for more than 140 seconds.
      Not tainted 4.19.120-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:6    D26096  7757      2 0x80000000
Workqueue: events_unbound fsnotify_mark_destroy_workfn
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_timeout+0x896/0xf20 kernel/time/timer.c:1782
 do_wait_for_common kernel/sched/completion.c:83 [inline]
 __wait_for_common kernel/sched/completion.c:104 [inline]
 wait_for_common kernel/sched/completion.c:115 [inline]
 wait_for_completion+0x26a/0x3c0 kernel/sched/completion.c:136
 __synchronize_srcu+0x12e/0x210 kernel/rcu/srcutree.c:936
 fsnotify_mark_destroy_workfn+0xfd/0x330 fs/notify/mark.c:795
 process_one_work+0x91f/0x1640 kernel/workqueue.c:2155
 worker_thread+0x96/0xe20 kernel/workqueue.c:2298
 kthread+0x34a/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
INFO: task syz-executor.3:15529 blocked for more than 140 seconds.
      Not tainted 4.19.120-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.3  D26880 15529   6759 0x00000004
Call Trace:
 schedule+0x8d/0x1b0 kernel/sched/core.c:3559
 schedule_timeout+0x896/0xf20 kernel/time/timer.c:1782
 do_wait_for_common kernel/sched/completion.c:83 [inline]
 __wait_for_common kernel/sched/completion.c:104 [inline]
 wait_for_common kernel/sched/completion.c:115 [inline]
 wait_for_completion+0x26a/0x3c0 kernel/sched/completion.c:136
 __flush_work+0x48b/0x870 kernel/workqueue.c:2928
 __cancel_work_timer+0x388/0x4f0 kernel/workqueue.c:3015
 p9_conn_destroy net/9p/trans_fd.c:878 [inline]
 p9_fd_close+0x29c/0x520 net/9p/trans_fd.c:913
 p9_client_create+0x98c/0x1400 net/9p/client.c:1084
 v9fs_session_init+0x1e7/0x18c0 fs/9p/v9fs.c:421
 v9fs_mount+0x79/0x900 fs/9p/vfs_super.c:135
 mount_fs+0xa3/0x30c fs/super.c:1261
 vfs_kern_mount.part.0+0x68/0x400 fs/namespace.c:961
 vfs_kern_mount fs/namespace.c:951 [inline]
 do_new_mount fs/namespace.c:2469 [inline]
 do_mount+0x4f4/0x2a40 fs/namespace.c:2799
 ksys_mount+0xd7/0x150 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xba/0x150 fs/namespace.c:3026
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c829
Code: Bad RIP value.
RSP: 002b:00007facf5033c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000004f6040 RCX: 000000000045c829
RDX: 0000000020000200 RSI: 00000000200001c0 RDI: 0000000000000000
RBP: 000000000078c040 R08: 00000000200002c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000752 R14: 00000000004ca115 R15: 00007facf50346d4

Showing all locks held in the system:
1 lock held by khungtaskd/1079:
 #0: 00000000844cfe47 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440
1 lock held by in:imklog/6174:
 #0: 00000000dee94be6 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xe3/0x100 fs/file.c:767
3 locks held by kworker/0:4/7599:
2 locks held by kworker/u4:5/7718:
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0x81a/0x1640 kernel/workqueue.c:2126
 #1: 000000005a70322d (connector_reaper_work){+.+.}, at: process_one_work+0x84e/0x1640 kernel/workqueue.c:2130
2 locks held by kworker/u4:6/7757:
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 00000000b22fddef ((wq_completion)"events_unbound"){+.+.}, at: process_one_work+0x81a/0x1640 kernel/workqueue.c:2126
 #1: 000000005341c293 ((reaper_work).work){+.+.}, at: process_one_work+0x84e/0x1640 kernel/workqueue.c:2130
2 locks held by syz-executor.3/15457:
 #0: 0000000034baa89d (epmutex){+.+.}, at: ep_free+0x6b/0x220 fs/eventpoll.c:829
 #1: 0000000097a4ff8b (&ep->mtx){+.+.}, at: ep_free+0xd2/0x220 fs/eventpoll.c:849

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

NMI backtrace for cpu 1
CPU: 1 PID: 1079 Comm: khungtaskd Not tainted 4.19.120-syzkaller #0
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+0x188/0x20d lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x962/0xe40 kernel/hung_task.c:287
 kthread+0x34a/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7599 Comm: kworker/0:4 Not tainted 4.19.120-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events p9_read_work
RIP: 0010:__lock_acquire+0x405/0x49c0 kernel/locking/lockdep.c:3359
Code: 00 00 49 8d 42 18 4d 89 7a 10 48 89 c2 48 89 44 24 58 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 3f 2e 00 00 <48> 8b 84 24 98 00 00 00 49 8d be 54 08 00 00 48 89 fa 48 c1 ea 03
RSP: 0018:ffff88804aecf650 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 00000000000007c1
RDX: 1ffff110095ce9be RSI: 1ffff110095ce9ba RDI: ffff88804ae74de8
RBP: ffff88804aecf820 R08: 0000000000000001 R09: 0000000000000002
R10: ffff88804ae74dd8 R11: 00000000000007c1 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88804ae74500 R15: ffff88809f9b9520
FS:  0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000556eb5c94e98 CR3: 0000000096605000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 lock_acquire+0x170/0x400 kernel/locking/lockdep.c:3907
 __mutex_lock_common kernel/locking/mutex.c:925 [inline]
 __mutex_lock+0xf7/0x1300 kernel/locking/mutex.c:1072
 snd_pcm_oss_read1 sound/core/oss/pcm_oss.c:1504 [inline]
 snd_pcm_oss_read+0x305/0x6a0 sound/core/oss/pcm_oss.c:2753
 __vfs_read+0xf7/0x740 fs/read_write.c:416
 vfs_read+0x18e/0x3b0 fs/read_write.c:452
 kernel_read+0xa6/0x110 fs/read_write.c:431
 p9_fd_read net/9p/trans_fd.c:278 [inline]
 p9_read_work+0x299/0xf70 net/9p/trans_fd.c:313
 process_one_work+0x91f/0x1640 kernel/workqueue.c:2155
 worker_thread+0x96/0xe20 kernel/workqueue.c:2298
 kthread+0x34a/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-linux-4-19 2020/05/05 10:35 linux-4.19.y fdc072324f3c 9941337c .config console log report
ci2-linux-4-19 2020/04/17 09:30 linux-4.19.y 8488c3f3bc86 18397578 .config console log report
* Struck through repros no longer work on HEAD.