INFO: task syz.1.701:11857 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kerne[ 716.651148][ T38] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.701 state:D stack:25800 pid:11857 tgid:11855 ppid:5839 task_flags:0x400140 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
kthread_flush_worker+0x1c6/0x240 kernel/kthread.c:1564
__alloc_workqueue+0x146b/0x1b70 kernel/workqueue.c:5763
alloc_workqueue_noprof+0xd4/0x210 kernel/workqueue.c:5786
btrfs_init_workqueues+0x42c/0x6c0 fs/btrfs/disk-io.c:2000
open_ctree+0x11ef/0x3a10 fs/btrfs/disk-io.c:3424
btrfs_fill_super fs/btrfs/super.c:977 [inline]
btrfs_get_tree_super fs/btrfs/super.c:1940 [inline]
btrfs_get_tree_subvol fs/btrfs/super.c:2077 [inline]
btrfs_get_tree+0xf55/0x1820 fs/btrfs/super.c:2111
vfs_get_tree+0x92/0x2b0 fs/super.c:1815
do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
do_mount fs/namespace.c:4136 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fce55dc038a
RSP: 002b:00007fce5401de68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fce5401def0 RCX: 00007fce55dc038a
RDX: 0000200000005100 RSI: 0000200000000280 RDI: 00007fce5401deb0
RBP: 0000200000005100 R08: 00007fce5401def0 R09: 0000000000000810
R10: 0000000000000810 R11: 0000000000000246 R12: 0000200000000280
R13: 00007fce5401deb0 R14: 000000000000510e R15: 0000200000000180
Showing all locks held in the system:
3 locks held by kworker/0:1/10:
1 lock held by khungtaskd/38:
#0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d9a8b80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:8/1287:
2 locks held by getty/5599:
#0: ffff88823bf408a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222
3 locks held by syz-executor/5838:
4 locks held by syz-executor/5840:
1 lock held by udevd/5980:
9 locks held by syz-executor/8915:
1 lock held by syz.1.701/11857:
#0: ffff888037cde0d0 (&type->s_umount_key#53/1){+.+.}-{4:4}, at: alloc_super+0x204/0x990 fs/super.c:345
2 locks held by syz-executor/12081:
4 locks held by syz.4.894/13710:
2 locks held by syz.0.893/13714:
2 locks held by syz.6.895/13735:
1 lock held by udevadm/13753:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5840 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:check_preemption_disabled+0x17/0x120 lib/smp_processor_id.c:14
Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 05 fe 74 ff 06 48 89 44 24 08 <65> 8b 05 06 75 ff 06 65 8b 0d fb 74 ff 06 f7 c1 ff ff ff 7f 74 23
RSP: 0018:ffffc90004a37850 EFLAGS: 00000086
RAX: 2c8cdb2dbce9a100 RBX: 0000000000000001 RCX: 2c8cdb2dbce9a100
RDX: 0000000000000001 RSI: ffffffff8d2187b4 RDI: ffffffff8b620e00
RBP: 00000000ffffffff R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000946ef8 R12: 0000000000000046
R13: ffff8880272b9dc0 R14: ffff8880278f8360 R15: 0000000000000003
FS: 0000555577d3e500(0000) GS:ffff8881269c2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdf18d3c08 CR3: 0000000055cfe000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
lock_is_held_type+0xfe/0x190 kernel/locking/lockdep.c:5941
lock_is_held include/linux/lockdep.h:249 [inline]
__rwbase_write_trylock kernel/locking/rwbase_rt.c:223 [inline]
rwbase_write_lock+0x1bb/0x750 kernel/locking/rwbase_rt.c:253
f2fs_down_write fs/f2fs/f2fs.h:2234 [inline]
f2fs_lock_all fs/f2fs/f2fs.h:2314 [inline]
block_operations fs/f2fs/checkpoint.c:1221 [inline]
f2fs_write_checkpoint+0x51c/0x1df0 fs/f2fs/checkpoint.c:1638
kill_f2fs_super+0x2c3/0x6c0 fs/f2fs/super.c:5347
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1375
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd92c73ff17
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007fff8d8069b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fd92c7c1c05 RCX: 00007fd92c73ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff8d806a70
RBP: 00007fff8d806a70 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff8d807b00
R13: 00007fd92c7c1c05 R14: 000000000004acf6 R15: 00007fff8d807b40