syzbot


INFO: task hung in do_unlinkat (2)

Status: auto-closed as invalid on 2021/05/17 08:41
Subsystems: fs
[Documentation on labels]
First crash: 1260d, last: 1260d
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in do_unlinkat (2) 1 602d 602d 0/1 auto-obsoleted due to no activity on 2023/03/27 07:50
android-49 INFO: task hung in do_unlinkat 5 2154d 2266d 0/3 auto-closed as invalid on 2019/02/24 11:49
upstream INFO: task hung in do_unlinkat (5) kernfs bcachefs 50 28d 49d 0/27 upstream: reported on 2024/06/02 14:09
upstream INFO: task hung in do_unlinkat exfat 34 2015d 2251d 0/27 closed as dup on 2018/10/27 13:26
upstream INFO: task hung in do_unlinkat (3) fs 2 979d 1022d 0/27 closed as invalid on 2022/02/07 19:19
linux-4.19 INFO: task hung in do_unlinkat 1 732d 732d 0/1 auto-obsoleted due to no activity on 2022/11/17 10:56
upstream INFO: task hung in do_unlinkat (4) exfat 4 571d 677d 0/27 auto-obsoleted due to no activity on 2023/04/08 02:53
linux-5.15 INFO: task hung in do_unlinkat 2 8h46m 70d 0/3 upstream: reported on 2024/05/12 15:06

Sample crash report:
INFO: task syz-executor.0:15959 blocked for more than 143 seconds.
      Not tainted 5.11.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:29632 pid:15959 ppid:  8454 flags:0x00000004
Call Trace:
 context_switch kernel/sched/core.c:4327 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5078
 schedule+0xcf/0x270 kernel/sched/core.c:5157
 rwsem_down_write_slowpath+0x7e5/0x1200 kernel/locking/rwsem.c:1106
 __down_write_common kernel/locking/rwsem.c:1261 [inline]
 __down_write_common kernel/locking/rwsem.c:1258 [inline]
 __down_write kernel/locking/rwsem.c:1270 [inline]
 down_write_nested+0x136/0x150 kernel/locking/rwsem.c:1517
 inode_lock_nested include/linux/fs.h:808 [inline]
 do_unlinkat+0x27d/0x660 fs/namei.c:3885
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x465b09
RSP: 002b:00007f5a2d74a188 EFLAGS: 00000246 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000465b09
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000000
RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007ffef4fd6a9f R14: 00007f5a2d74a300 R15: 0000000000022000
INFO: task syz-executor.0:15965 blocked for more than 143 seconds.
      Not tainted 5.11.0-rc6-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:27776 pid:15965 ppid:  8454 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4327 [inline]
 __schedule+0x90c/0x21a0 kernel/sched/core.c:5078
 schedule+0xcf/0x270 kernel/sched/core.c:5157
 rwsem_down_write_slowpath+0x7e5/0x1200 kernel/locking/rwsem.c:1106
 __down_write_common kernel/locking/rwsem.c:1261 [inline]
 __down_write_common kernel/locking/rwsem.c:1258 [inline]
 __down_write kernel/locking/rwsem.c:1270 [inline]
 down_write+0x132/0x150 kernel/locking/rwsem.c:1407
 inode_lock include/linux/fs.h:773 [inline]
 lock_mount+0x8a/0x2e0 fs/namespace.c:2198
 do_new_mount_fc fs/namespace.c:2824 [inline]
 do_new_mount fs/namespace.c:2883 [inline]
 path_mount+0x1787/0x20c0 fs/namespace.c:3211
 do_mount fs/namespace.c:3224 [inline]
 __do_sys_mount fs/namespace.c:3432 [inline]
 __se_sys_mount fs/namespace.c:3409 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3409
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x465b09
RSP: 002b:00007f5a2d729188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 000000000056c0b0 RCX: 0000000000465b09
RDX: 0000000020002000 RSI: 00000000200042c0 RDI: 0000000000000000
RBP: 00000000004b069f R08: 0000000020002140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0b0
R13: 00007ffef4fd6a9f R14: 00007f5a2d729300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/1649:
 #0: ffffffff8bd73e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6259
1 lock held by in:imklog/8148:
 #0: ffff888029ab5b30 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947
3 locks held by syz-executor.0/15952:
2 locks held by syz-executor.0/15959:
 #0: ffff888013078460 (sb_writers#22){.+.+}-{0:0}, at: do_unlinkat+0x190/0x660 fs/namei.c:3881
 #1: ffff888077b14850 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:808 [inline]
 #1: ffff888077b14850 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: do_unlinkat+0x27d/0x660 fs/namei.c:3885
1 lock held by syz-executor.0/15965:
 #0: ffff888077b14850 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:773 [inline]
 #0: ffff888077b14850 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lock_mount+0x8a/0x2e0 fs/namespace.c:2198

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

NMI backtrace for cpu 1
CPU: 1 PID: 1649 Comm: khungtaskd Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:120
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd43/0xfa0 kernel/hung_task.c:294
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4884 Comm: systemd-journal Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mark_held_locks+0x82/0xe0 kernel/locking/lockdep.c:4004
Code: 57 48 63 c3 48 8d 04 80 49 8d 34 c6 48 8d 7e 22 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 42 0f b6 04 28 38 d0 7f 04 84 c0 75 4a <0f> b6 46 22 89 c2 83 e2 03 80 fa 01 89 ea 83 da ff a8 04 74 0c 4c
RSP: 0018:ffffc90001557c20 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81585257
RDX: 0000000000000002 RSI: ffff888015db8a88 RDI: ffff888015db8aaa
RBP: 0000000000000006 R08: 0000000000000000 R09: ffffffff8f87584f
R10: fffffbfff1f0eb09 R11: 0000000000000000 R12: ffff888015db8100
R13: dffffc0000000000 R14: ffff888015db8a88 R15: 0000000000000001
FS:  00007fc446cdf8c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc4441c4000 CR3: 00000000159b4000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4038 [inline]
 lockdep_hardirqs_on_prepare kernel/locking/lockdep.c:4098 [inline]
 lockdep_hardirqs_on_prepare+0x28b/0x400 kernel/locking/lockdep.c:4050
 trace_hardirqs_on+0x5b/0x1c0 kernel/trace/trace_preemptirq.c:49
 __raw_write_unlock_irq include/linux/rwlock_api_smp.h:267 [inline]
 _raw_write_unlock_irq+0x1f/0x40 kernel/locking/spinlock.c:343
 ep_send_events fs/eventpoll.c:1709 [inline]
 ep_poll fs/eventpoll.c:1792 [inline]
 do_epoll_wait+0x105a/0x1920 fs/eventpoll.c:2220
 __do_sys_epoll_wait fs/eventpoll.c:2232 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2227 [inline]
 __x64_sys_epoll_wait+0x158/0x270 fs/eventpoll.c:2227
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fc445fa82e3
Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 83 3d 29 54 2b 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 0b c2 00 00 48 89 04 24
RSP: 002b:00007ffd6cc6aae8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 000055d9663a4200 RCX: 00007fc445fa82e3
RDX: 0000000000000013 RSI: 00007ffd6cc6aaf0 RDI: 0000000000000008
RBP: 00007ffd6cc6ace0 R08: 000055d9663a6590 R09: 00007ffd6cc96080
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd6cc6aaf0
R13: 0000000000000001 R14: ffffffffffffffff R15: 0005babf2241f8a6

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/02/07 13:36 upstream 825b5991a46e 2ce644fc .config console log report info ci-upstream-kasan-gce-selinux-root INFO: task hung in do_unlinkat
2021/02/07 12:55 upstream 825b5991a46e 2ce644fc .config console log report info ci-upstream-kasan-gce-smack-root INFO: task hung in do_unlinkat
2021/02/07 10:00 upstream 825b5991a46e 2ce644fc .config console log report info ci-upstream-kasan-gce INFO: task hung in do_unlinkat
2021/02/07 11:49 upstream 825b5991a46e 2ce644fc .config console log report info ci-upstream-kasan-gce-386 INFO: task hung in do_unlinkat
* Struck through repros no longer work on HEAD.