syzbot


INFO: task hung in fuse_kill_sb_anon (2)

Status: auto-closed as invalid on 2022/01/10 01:04
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 438d, last: 412d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in fuse_kill_sb_anon 2 711d 711d 0/24 auto-closed as invalid on 2021/03/17 02:28
android-49 INFO: task hung in fuse_kill_sb_anon 1 1547d 1547d 0/3 auto-closed as invalid on 2019/03/02 00:11

Sample crash report:
INFO: task syz-executor.5:19118 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:23944 pid:19118 ppid:     1 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0x940/0x26f0 kernel/sched/core.c:6287
 schedule+0xd3/0x270 kernel/sched/core.c:6366
 rwsem_down_write_slowpath+0x7b9/0x11d0 kernel/locking/rwsem.c:1107
 __down_write_common kernel/locking/rwsem.c:1262 [inline]
 __down_write_common kernel/locking/rwsem.c:1259 [inline]
 __down_write kernel/locking/rwsem.c:1271 [inline]
 down_write+0x137/0x150 kernel/locking/rwsem.c:1518
 fuse_mount_remove fs/fuse/inode.c:1716 [inline]
 fuse_sb_destroy fs/fuse/inode.c:1751 [inline]
 fuse_kill_sb_anon+0x81/0x290 fs/fuse/inode.c:1759
 deactivate_locked_super+0x94/0x160 fs/super.c:335
 deactivate_super+0xad/0xd0 fs/super.c:366
 cleanup_mnt+0x3a2/0x540 fs/namespace.c:1137
 task_work_run+0xdd/0x1a0 kernel/task_work.c:164
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
 exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
 __syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
 syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
 do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7ff3802b6d37
RSP: 002b:00007ffe347d3f78 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007ff3802b6d37
RDX: 00007ffe347d404b RSI: 0000000000000002 RDI: 00007ffe347d4040
RBP: 00007ffe347d4040 R08: 00000000ffffffff R09: 00007ffe347d3e10
R10: 0000555555b318e3 R11: 0000000000000206 R12: 00007ff38030ee80
R13: 00007ffe347d5100 R14: 0000555555b31810 R15: 00007ffe347d5140

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8b97fea0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446
2 locks held by in:imklog/6228:
 #0: ffff88801df560f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990
 #1: ffffffff8b96f328 (syslog_lock){+.+.}-{3:3}, at: raw_spin_rq_lock_nested kernel/sched/core.c:474 [inline]
 #1: ffffffff8b96f328 (syslog_lock){+.+.}-{3:3}, at: raw_spin_rq_lock kernel/sched/sched.h:1317 [inline]
 #1: ffffffff8b96f328 (syslog_lock){+.+.}-{3:3}, at: rq_lock kernel/sched/sched.h:1620 [inline]
 #1: ffffffff8b96f328 (syslog_lock){+.+.}-{3:3}, at: __schedule+0x236/0x26f0 kernel/sched/core.c:6201
4 locks held by kworker/u4:10/13881:
2 locks held by syz-executor.5/19118:
 #0: ffff888034df60e0 (&type->s_umount_key#78){+.+.}-{3:3}, at: deactivate_super+0xa5/0xd0 fs/super.c:365
 #1: ffff888086ffa338 (&fc->killsb){++++}-{3:3}, at: fuse_mount_remove fs/fuse/inode.c:1716 [inline]
 #1: ffff888086ffa338 (&fc->killsb){++++}-{3:3}, at: fuse_sb_destroy fs/fuse/inode.c:1751 [inline]
 #1: ffff888086ffa338 (&fc->killsb){++++}-{3:3}, at: fuse_kill_sb_anon+0x81/0x290 fs/fuse/inode.c:1759
1 lock held by syz-executor.5/26318:
 #0: ffff888086ffa338 (&fc->killsb){++++}-{3:3}, at: fuse_notify_retrieve fs/fuse/dev.c:1749 [inline]
 #0: ffff888086ffa338 (&fc->killsb){++++}-{3:3}, at: fuse_notify fs/fuse/dev.c:1787 [inline]
 #0: ffff888086ffa338 (&fc->killsb){++++}-{3:3}, at: fuse_dev_do_write+0xffc/0x2bd0 fs/fuse/dev.c:1865

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xc1d/0xf50 kernel/hung_task.c:295
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13171 Comm: kworker/u4:9 Not tainted 5.15.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4704 [inline]
RIP: 0010:__lock_acquire+0x562/0x54a0 kernel/locking/lockdep.c:4965
Code: 0f 8e 88 10 00 00 41 8b b5 f0 09 00 00 41 89 f6 41 83 ee 01 0f 88 67 12 00 00 49 b8 00 00 00 00 00 fc ff df 49 63 c6 41 89 d7 <48> 8d 04 80 49 8d ac c5 19 0a 00 00 eb 12 41 83 ee 01 48 83 ed 28
RSP: 0018:ffffc9000325fa60 EFLAGS: 00000002
RAX: 0000000000000001 RBX: ffffffff8b97fea0 RCX: 1ffff110114bbbee
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffffffff8fcfebf9
RBP: ffffffff8fcfeb40 R08: dffffc0000000000 R09: ffffffff8fcfc927
R10: fffffbfff1f9f924 R11: 0000000000000000 R12: ffff88808a5ddfc8
R13: ffff88808a5dd580 R14: 0000000000000001 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa8dcb49000 CR3: 000000001d9dd000 CR4: 0000000000350ee0
Call Trace:
 lock_acquire kernel/locking/lockdep.c:5625 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5590
 rcu_lock_acquire include/linux/rcupdate.h:267 [inline]
 rcu_read_lock include/linux/rcupdate.h:687 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:410 [inline]
 batadv_nc_worker+0x12d/0xfa0 net/batman-adv/network-coding.c:721
 process_one_work+0x9bf/0x16b0 kernel/workqueue.c:2297
 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
----------------
Code disassembly (best guess):
   0:	0f 8e 88 10 00 00    	jle    0x108e
   6:	41 8b b5 f0 09 00 00 	mov    0x9f0(%r13),%esi
   d:	41 89 f6             	mov    %esi,%r14d
  10:	41 83 ee 01          	sub    $0x1,%r14d
  14:	0f 88 67 12 00 00    	js     0x1281
  1a:	49 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%r8
  21:	fc ff df
  24:	49 63 c6             	movslq %r14d,%rax
  27:	41 89 d7             	mov    %edx,%r15d
* 2a:	48 8d 04 80          	lea    (%rax,%rax,4),%rax <-- trapping instruction
  2e:	49 8d ac c5 19 0a 00 	lea    0xa19(%r13,%rax,8),%rbp
  35:	00
  36:	eb 12                	jmp    0x4a
  38:	41 83 ee 01          	sub    $0x1,%r14d
  3c:	48 83 ed 28          	sub    $0x28,%rbp

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2021/10/12 01:04 upstream 64570fbc14f8 838e7e2c .config log report info INFO: task hung in fuse_kill_sb_anon
ci-upstream-kasan-gce-selinux-root 2021/09/25 16:31 upstream 7d42e9818258 8cac236e .config log report info INFO: task hung in fuse_kill_sb_anon
ci-upstream-kasan-gce 2021/09/16 07:20 upstream b7213ffa0e58 07e953c1 .config log report info INFO: task hung in fuse_kill_sb_anon
* Struck through repros no longer work on HEAD.