INFO: task kworker/u8:7:175 blocked for more than 143 seconds.
Tainted: G W syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:7 state:D stack:20000 [ 437.194044][ T39] task:kworker/u8:7 state:D stack:20000 pid:175 tgid:175 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:3)
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]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339
rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline]
mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547
jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:132
write_inode fs/fs-writeback.c:1525 [inline]
__writeback_single_inode+0x6f1/0x1000 fs/fs-writeback.c:1745
writeback_sb_inodes+0x6b7/0xf60 fs/fs-writeback.c:1976
wb_writeback+0x43b/0xaf0 fs/fs-writeback.c:2156
wb_do_writeback fs/fs-writeback.c:2303 [inline]
wb_workfn+0x40e/0xf00 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/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
INFO: task syz.3.342:9114 blocked for more than 143 seconds.
Tainted: G W syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.342 state:D stack:27024 pid:9114 tgid:9061 ppid:8423 task_flags:0x400140 flags:0x00004004
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
wb_wait_for_completion+0x15f/0x260 fs/fs-writeback.c:216
__writeback_inodes_sb_nr+0x1f7/0x270 fs/fs-writeback.c:2748
sync_filesystem+0xa2/0x250 fs/sync.c:54
jfs_reconfigure+0xc6/0xa00 fs/jfs/super.c:370
reconfigure_super+0x224/0x890 fs/super.c:1077
do_remount fs/namespace.c:3324 [inline]
path_mount+0xd18/0xfe0 fs/namespace.c:4115
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: 0033:0x7f4bfefd038a
RSP: 002b:00007f4bfd1f3e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f4bfd1f3ef0 RCX: 00007f4bfefd038a
RDX: 0000200000000f40 RSI: 0000200000000f00 RDI: 0000000000000000
RBP: 0000200000000f40 R08: 00007f4bfd1f3ef0 R09: 0000000001258438
R10: 0000000001258438 R11: 0000000000000246 R12: 0000200000000f00
R13: 00007f4bfd1f3eb0 R14: 0000000000000000 R15: 0000200000000f80
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Tainted: G W syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [W]=WARN
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+0x70e/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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 10731 Comm: syz-executor Tainted: G W syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline]
RIP: 0010:__rt_spin_lock kernel/locking/spinlock_rt.c:48 [inline]
RIP: 0010:rt_spin_lock+0x8c/0x2c0 kernel/locking/spinlock_rt.c:57
Code: f3 f3 48 89 4c 24 18 4a 89 04 21 48 83 c7 58 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 ff 75 08 e8 48 65 a3 f6 48 83 c4 08 <65> 4c 8b 34 25 08 c0 f5 91 4d 8d be 44 04 00 00 4c 89 f8 48 c1 e8
RSP: 0018:ffffc90005647600 EFLAGS: 00000296
RAX: efa404be6df50400 RBX: ffff888066ba0a00 RCX: efa404be6df50400
RDX: 0000000000000000 RSI: ffffffff8b620c60 RDI: ffffffff8b620c20
RBP: ffffc900056476c0 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc90005647740 R11: fffff52000ac8f16 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888066ba0980 R15: ffffc90005647740
FS: 000055558c2b9500(0000) GS:ffff8881268c4000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557dd79808 CR3: 000000005b7c8000 CR4: 00000000003526f0
Call Trace:
spin_lock include/linux/spinlock_rt.h:44 [inline]
writeback_single_inode+0x36/0x640 fs/fs-writeback.c:1769
sync_inode_metadata+0xb9/0x110 fs/fs-writeback.c:2884
f2fs_sync_inode_meta fs/f2fs/checkpoint.c:1152 [inline]
block_operations fs/f2fs/checkpoint.c:1263 [inline]
f2fs_write_checkpoint+0xb06/0x1df0 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: 0033:0x7f87b18bff17
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:00007ffc57d90438 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f87b1941c05 RCX: 00007f87b18bff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc57d904f0
RBP: 00007ffc57d904f0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc57d91580
R13: 00007f87b1941c05 R14: 00000000000671c7 R15: 00007ffc57d915c0