INFO: task syz-executor.0:4501 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D
stack:21856 pid: 4501 ppid: 1 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191
sync_inodes_sb+0x1b3/0x920 fs/fs-writeback.c:2770
sync_filesystem+0x16d/0x220 fs/sync.c:64
generic_shutdown_super+0x6b/0x300 fs/super.c:448
kill_block_super+0x7c/0xe0 fs/super.c:1427
deactivate_locked_super+0x93/0xf0 fs/super.c:335
cleanup_mnt+0x418/0x4d0 fs/namespace.c:1139
task_work_run+0x125/0x1a0 kernel/task_work.c:188
tracehook_notify_resume include/linux/tracehook.h:189 [inline]
exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1a89534c07
RSP: 002b:00007fff3ddacea8 EFLAGS: 00000246
ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f1a8958eaf2 RCX: 00007f1a89534c07
RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007fff3ddacf60
RBP: 00007fff3ddacf60 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff3ddae020
R13: 00007f1a8958eaf2 R14: 00000000000109c3 R15: 0000000000000003
Showing all locks held in the system:
5 locks held by kworker/1:0/21:
1 lock held by khungtaskd/27:
#0:
ffffffff8c11c460
(
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:2/154:
#0:
ffff8880199f0938
(
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1:
ffffc90002077d00
(
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2:
ffff888078c66650
(
sb_internal
#2){.+.+}-{0:0}, at: lockdep_copy_map include/linux/lockdep.h:45 [inline]
#2){.+.+}-{0:0}, at: call_timer_fn+0xbb/0x530 kernel/time/timer.c:1441
#3:
ffff888073e980e8
(
&xfs_nondir_ilock_class
){++++}-{3:3}
, at: xfs_bmapi_convert_delalloc+0x21e/0xd90 fs/xfs/libxfs/xfs_bmap.c:4578
2 locks held by getty/3945:
#0:
ffff88802c209098
(
&tty->ldisc_sem
){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1:
ffffc900025ce2e8
(
&ldata->atomic_read_lock
){+.+.}-{3:3}
, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
2 locks held by syz-executor.0/4501:
#0:
ffff888078c660e0
(
&type->s_umount_key
#51
){+.+.}-{3:3}
, at: deactivate_super+0xa0/0xd0 fs/super.c:365
#1:
ffff8880201207d8
(
&bdi->wb_switch_rwsem
){+.+.}-{3:3}
, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2768
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 154 Comm: kworker/u4:2 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:205
Code: 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 30 c4 f1 0b 48 89 de 5b e9 67 9c 43 00 00 00 cc cc 00 00 cc 48 8b 04 24 <65> 48 8b 0d 04 a5 8a 7e 65 8b 15 05 a5 8a 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc900020765b8 EFLAGS: 00000213
RAX: ffffffff83fe0285 RBX: 00000000ffffffff RCX: ffff88801b7f1dc0
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000000000003
RBP: ffffc900020766e0 R08: dffffc0000000000 R09: ffffc90002076640
R10: fffff5200040eccb R11: 1ffff9200040ecc8 R12: ffffffffffffffff
R13: 0000000000000003 R14: ffffc900020769c3 R15: 0000000000000003
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c08b21b168 CR3: 000000007bc8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
number+0xb65/0xf70 lib/vsprintf.c:552
vsnprintf+0x10fe/0x1a00 lib/vsprintf.c:2877
sprintf+0xd6/0x120 lib/vsprintf.c:3013
print_time kernel/printk/printk.c:1274 [inline]
info_print_prefix+0x152/0x300 kernel/printk/printk.c:1300
record_print_text kernel/printk/printk.c:1349 [inline]
console_unlock+0x7f5/0x1200 kernel/printk/printk.c:2725
vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
_printk+0xcc/0x110 kernel/printk/printk.c:2299
__xfs_printk fs/xfs/xfs_message.c:24 [inline]
xfs_alert+0x188/0x280 fs/xfs/xfs_message.c:52
xfs_discard_page+0x1a4/0x4a0 fs/xfs/xfs_aops.c:455
iomap_writepage_map fs/iomap/buffered-io.c:1351 [inline]
iomap_do_writepage+0x1c58/0x2120 fs/iomap/buffered-io.c:1485
write_cache_pages+0x984/0xfa0 mm/page-writeback.c:2277
iomap_writepages+0x5a/0x210 fs/iomap/buffered-io.c:1516
xfs_vm_writepages+0x129/0x180 fs/xfs/xfs_aops.c:488
do_writepages+0x48d/0x6d0 mm/page-writeback.c:2386
__writeback_single_inode+0x153/0xda0 fs/fs-writeback.c:1647
writeback_sb_inodes+0x9fe/0x1610 fs/fs-writeback.c:1930
wb_writeback+0x443/0xb90 fs/fs-writeback.c:2104
wb_do_writeback fs/fs-writeback.c:2247 [inline]
wb_workfn+0x423/0xe60 fs/fs-writeback.c:2288
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287