INFO: task kworker/u8:17:18617 blocked for more than 143 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:17 state:D stack:24920 pid:18617 tgid:18617 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:4)
Call Trace:
context_switch kernel/sched/core.c:5504 [inline]
__schedule+0x16dc/0x5500 kernel/sched/core.c:7228
__schedule_loop kernel/sched/core.c:7307 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7603
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1670 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked+0x1f84/0x25b0 kernel/locking/rtmutex.c:1787
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1827
__rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline]
rwbase_write_lock+0x14c/0x720 kernel/locking/rwbase_rt.c:251
f2fs_down_write fs/f2fs/f2fs.h:2411 [inline]
f2fs_down_write_trace fs/f2fs/checkpoint.c:180 [inline]
f2fs_issue_checkpoint+0x407/0x770 fs/f2fs/checkpoint.c:2095
f2fs_balance_fs_bg+0x571/0x9d0 fs/f2fs/segment.c:545
f2fs_write_node_pages+0x158/0x700 fs/f2fs/node.c:2257
do_writepages+0x338/0x560 mm/page-writeback.c:2571
__writeback_single_inode+0x12e/0xf90 fs/fs-writeback.c:1787
writeback_sb_inodes+0x9db/0x1ab0 fs/fs-writeback.c:2079
__writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2155
wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2266
wb_check_old_data_flush fs/fs-writeback.c:2370 [inline]
wb_do_writeback fs/fs-writeback.c:2449 [inline]
wb_workfn+0xc98/0x10f0 fs/fs-writeback.c:2477
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
INFO: lockdep is turned off.
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 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
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: 3311 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: loop8 loop_workfn
RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:202 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:232 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:folio_test_idle include/linux/page-flags.h:667 [inline]
RIP: 0010:folio_mark_accessed+0x2df/0x4a0 mm/swap.c:492
Code: 89 fe 48 83 e6 01 31 ff e8 3e b6 be ff 49 83 e7 01 0f 85 28 01 00 00 48 89 df be 08 00 00 00 e8 b7 f2 25 00 43 80 7c 25 00 00 <74> 08 48 89 df e8 37 f0 25 00 4c 8b 3b 4c 89 fe 48 81 e6 00 00 40
RSP: 0018:ffffc9000f12f288 EFLAGS: 00000246
RAX: ffffffff82060b01 RBX: ffffea0001058800 RCX: ffffffff82060b29
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffea0001058800
RBP: 1ffffd400020b101 R08: ffffea0001058807 R09: 1ffffd400020b100
R10: dffffc0000000000 R11: fffff9400020b101 R12: dffffc0000000000
R13: 1ffffd400020b100 R14: ffffea0001058808 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812647d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f11f871d000 CR3: 000000005d790000 CR4: 00000000003526f0
Call Trace:
shmem_get_folio_gfp+0xc8d/0x1b70 mm/shmem.c:2514
shmem_get_folio mm/shmem.c:2668 [inline]
shmem_write_begin+0x166/0x320 mm/shmem.c:3302
generic_perform_write+0x2ad/0x8b0 mm/filemap.c:4336
shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3477
lo_rw_aio+0xc78/0xf30 include/linux/percpu-rwsem.h:-1
do_req_filebacked drivers/block/loop.c:429 [inline]
loop_handle_cmd drivers/block/loop.c:1921 [inline]
loop_process_work+0x638/0x11d0 drivers/block/loop.c:1956
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245