INFO: task syz-executor.0:4464 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:22016 pid: 4464 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: 0033:0x7f299d8c8c07
RSP: 002b:00007ffee7237018 EFLAGS: 00000246
ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f299d922aa2 RCX: 00007f299d8c8c07
RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007ffee72370d0
RBP: 00007ffee72370d0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffee7238190
R13: 00007f299d922aa2 R14: 0000000000010a6c R15: 0000000000000003
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0:
ffffffff8c11c460
(
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire+0x0/0x30
4 locks held by kworker/u4:5/3094:
#0:
ffff888142de0938
(
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1:
ffffc9000d5afd00
(
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2:
ffff88801a38e650
(
sb_internal
#2
){.+.+}-{0:0}
, at: xfs_bmapi_convert_delalloc+0x1f1/0xd90 fs/xfs/libxfs/xfs_bmap.c:4573
#3:
ffff88806d0700e8
(
&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/3948:
#0:
ffff88814cbe1098
(
&tty->ldisc_sem
){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1:
ffffc90002cf62e8
(
&ldata->atomic_read_lock
){+.+.}-{3:3}
, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
5 locks held by kworker/1:4/4208:
2 locks held by syz-executor.0/4464:
#0:
ffff88801a38e0e0
(
&type->s_umount_key
#51
){+.+.}-{3:3}
, at: deactivate_super+0xa0/0xd0 fs/super.c:365
#1:
ffff8880201f67d8
(
&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: 4208 Comm: kworker/1:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: xfs-buf/loop0 xfs_buf_ioend_work
RIP: 0010:io_serial_in+0x73/0xb0 drivers/tty/serial/8250/8250_port.c:461
Code: e8 12 51 32 fd 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 23 b7 76 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 44 89 f9 80 e1 07 38 c1 7c aa 4c
RSP: 0018:ffffc900031cf370 EFLAGS: 00000002
RAX: 1ffffffff2c7d060 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: 0000000000000020 R08: 0000000000000004 R09: 0000000000000003
R10: fffff52000639e64 R11: 1ffff92000639e64 R12: dffffc0000000000
R13: 1ffffffff2c20930 R14: ffffffff963e87e0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000558d640c8168 CR3: 000000007e1ba000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:116 [inline]
wait_for_xmitr+0x4c/0x260 drivers/tty/serial/8250/8250_port.c:2069
serial8250_console_putchar+0x1a/0x50 drivers/tty/serial/8250/8250_port.c:3309
uart_console_write+0xaa/0x100 drivers/tty/serial/serial_core.c:1981
serial8250_console_write+0xbb5/0xf80 drivers/tty/serial/8250/8250_port.c:3386
call_console_drivers kernel/printk/printk.c:-1 [inline]
console_unlock+0xc86/0x1200 kernel/printk/printk.c:2744
vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274
_printk+0xcc/0x110 kernel/printk/printk.c:2299
print_hex_dump+0x1a5/0x260 lib/hexdump.c:285
xfs_hex_dump+0x39/0x50 fs/xfs/xfs_message.c:118
xfs_buf_verifier_error+0x1ba/0x290 fs/xfs/xfs_error.c:418
xfs_allocbt_read_verify+0x53/0xd0 fs/xfs/libxfs/xfs_alloc_btree.c:-1
xfs_buf_ioend+0x25c/0x6e0 fs/xfs/xfs_buf.c:1263
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