syzbot


INFO: task hung in fuse_kill_sb_anon

Status: auto-closed as invalid on 2021/03/17 02:28
Subsystems: fuse
[Documentation on labels]
First crash: 1226d, last: 1226d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 INFO: task hung in fuse_kill_sb_anon 1 2062d 2062d 0/3 auto-closed as invalid on 2019/03/02 00:11
upstream INFO: task hung in fuse_kill_sb_anon (2) fuse 3 927d 953d 0/26 auto-closed as invalid on 2022/01/10 01:04

Sample crash report:
INFO: task syz-executor.2:8518 blocked for more than 143 seconds.
      Not tainted 5.10.0-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:24024 pid: 8518 ppid:     1 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4327 [inline]
 __schedule+0x8eb/0x21b0 kernel/sched/core.c:5078
 schedule+0xcf/0x270 kernel/sched/core.c:5157
 rwsem_down_write_slowpath+0x809/0x1220 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
 fuse_mount_remove fs/fuse/inode.c:1531 [inline]
 fuse_kill_sb_anon+0x81/0x290 fs/fuse/inode.c:1566
 deactivate_locked_super+0x94/0x160 fs/super.c:335
 deactivate_super+0xad/0xd0 fs/super.c:366
 cleanup_mnt+0x3a3/0x530 fs/namespace.c:1118
 task_work_run+0xdd/0x190 kernel/task_work.c:168
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x1f0/0x200 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x460b77
RSP: 002b:00007ffe71fa4e38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000460b77
RDX: 00000000004032c8 RSI: 0000000000000002 RDI: 00007ffe71fa4ee0
RBP: 000000000000018b R08: 0000000000000000 R09: 000000000000000b
R10: 0000000000000005 R11: 0000000000000246 R12: 00007ffe71fa5f70
R13: 0000000001bcfa60 R14: 0000000000000000 R15: 00000000000758bf

Showing all locks held in the system:
1 lock held by khungtaskd/1646:
 #0: ffffffff8b78e020 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x28c kernel/locking/lockdep.c:6254
1 lock held by systemd-journal/4877:
1 lock held by in:imklog/8388:
 #0: ffff88801394f8b0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:947
2 locks held by syz-executor.2/8518:
 #0: ffff8880290800e0 (&type->s_umount_key#64){+.+.}-{3:3}, at: deactivate_super+0xa5/0xd0 fs/super.c:365
 #1: ffff8880198a5b38 (&fc->killsb){++++}-{3:3}, at: fuse_mount_remove fs/fuse/inode.c:1531 [inline]
 #1: ffff8880198a5b38 (&fc->killsb){++++}-{3:3}, at: fuse_kill_sb_anon+0x81/0x290 fs/fuse/inode.c:1566
1 lock held by syz-executor.2/12930:
 #0: ffff8880198a5b38 (&fc->killsb){++++}-{3:3}, at: fuse_notify_retrieve fs/fuse/dev.c:1743 [inline]
 #0: ffff8880198a5b38 (&fc->killsb){++++}-{3:3}, at: fuse_notify fs/fuse/dev.c:1781 [inline]
 #0: ffff8880198a5b38 (&fc->killsb){++++}-{3:3}, at: fuse_dev_do_write+0xfdd/0x2c10 fs/fuse/dev.c:1859

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

NMI backtrace for cpu 0
CPU: 0 PID: 1646 Comm: khungtaskd Not tainted 5.10.0-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+0x3c/0xef 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+0xe36/0x10b0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8740 Comm: kworker/u4:3 Not tainted 5.10.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: phy10 ieee80211_iface_work
RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:99 [inline]
RIP: 0010:do_raw_spin_unlock+0x85/0x230 kernel/locking/spinlock_debug.c:138
Code: ff df 48 c1 ea 03 0f b6 14 02 48 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 6b 01 00 00 8b 45 00 85 c0 0f 84 f4 00 00 00 <4c> 8d 6d 10 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80
RSP: 0018:ffffc900023bfcf0 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000100 RCX: ffffffff81587040
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888010871800
RBP: ffff888010871800 R08: 0000000000000000 R09: ffff888010871803
R10: ffffed100210e300 R11: 0000000000000000 R12: 0000000000000001
R13: ffff8880794395c0 R14: ffff88801f01ac00 R15: ffff888010871800
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6fe5024000 CR3: 00000000136b5000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:167 [inline]
 _raw_spin_unlock_irq+0x1a/0x40 kernel/locking/spinlock.c:199
 process_one_work+0x883/0x1630 kernel/workqueue.c:2248
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/12/17 02:24 upstream 5e60366d56c6 04201c06 .config console log report info ci-upstream-kasan-gce-selinux-root
2020/12/17 02:06 upstream 5e60366d56c6 04201c06 .config console log report info ci-upstream-kasan-gce-386
* Struck through repros no longer work on HEAD.