INFO: task kworker/u8:9:4708 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9 state:D stack:20016 pid:4708 tgid:4708 ppid:2 task_flags:0x4208160 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:8)
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
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+0x6ee/0xff0 fs/fs-writeback.c:1745
writeback_sb_inodes+0x6c7/0x1010 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+0x409/0xef0 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: task syz.8.2847:18973 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.2847 state:D stack:25552 pid:18973 tgid:18965 ppid:17773 task_flags:0x400140 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 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+0x1f6/0x250 fs/fs-writeback.c:2748
sync_filesystem+0xa3/0x230 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:4117
do_mount fs/namespace.c:4138 [inline]
__do_sys_mount fs/namespace.c:4349 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4326
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f521979038a
RSP: 002b:00007f521a5abe68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f521a5abef0 RCX: 00007f521979038a
RDX: 0000200000000180 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 0000200000000180 R08: 00007f521a5abef0 R09: 0000000002046022
R10: 0000000002046022 R11: 0000000000000246 R12: 0000200000000000
R13: 00007f521a5abeb0 R14: 0000000000000000 R15: 00002000000002c0
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(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:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x47c/0x820 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: 21131 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:get_data+0x136/0x860 kernel/printk/printk_ringbuffer.c:1239
Code: 90 66 1e 00 4d 39 e5 0f 85 02 01 00 00 48 bb 00 00 00 00 00 fc ff df 48 8b 44 24 18 80 3c 18 00 74 08 4c 89 f7 e8 da 0d 82 00 <49> 8b 2e 4d 89 fc 49 c1 ec 03 41 80 3c 1c 00 74 08 4c 89 ff e8 c1
RSP: 0018:ffffc900036a7360 EFLAGS: 00000246
RAX: 1ffff920006d4e95 RBX: dffffc0000000000 RCX: ffff88802dedbc00
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000004
RBP: 0000000000000012 R08: 0000000000004fa7 R09: 000000c5c973de17
R10: 000000c5c973de17 R11: 0000001f82000020 R12: 0000000000000004
R13: 0000000000000004 R14: ffffc900036a74a8 R15: ffffc900036a74b0
FS: 000055558952f500(0000) GS:ffff8881259ff000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb0c0772020 CR3: 000000002e4e8000 CR4: 00000000003526f0
Call Trace:
copy_data kernel/printk/printk_ringbuffer.c:1830 [inline]
prb_read kernel/printk/printk_ringbuffer.c:1939 [inline]
_prb_read_valid+0x672/0xa90 kernel/printk/printk_ringbuffer.c:2116
prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2188
printk_get_next_message+0x15c/0x7b0 kernel/printk/printk.c:3005
console_emit_next_record kernel/printk/printk.c:3092 [inline]
console_flush_all+0x4ca/0xc40 kernel/printk/printk.c:3226
__console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
_printk+0xcf/0x120 kernel/printk/printk.c:2475
__xfs_printk fs/xfs/xfs_message.c:24 [inline]
xfs_printk_level+0x18b/0x280 fs/xfs/xfs_message.c:44
xfs_fs_put_super+0x55/0x160 fs/xfs/xfs_super.c:1245
generic_shutdown_super+0x135/0x2c0 fs/super.c:643
kill_block_super+0x44/0x90 fs/super.c:1723
xfs_kill_sb+0x15/0x50 fs/xfs/xfs_super.c:2317
deactivate_locked_super+0xb9/0x130 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/0x130 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/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe38158ff17
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:00007ffeddc53668 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe381611c05 RCX: 00007fe38158ff17
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffeddc53720
RBP: 00007ffeddc53720 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffeddc547b0
R13: 00007fe381611c05 R14: 00000000000cf3b1 R15: 00007ffeddc547f0