INFO: task syz-executor:4829 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 state:D stack:21824 pid: 4829 ppid: 1 flags:0x00004004
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
__writeback_inodes_sb_nr+0x1f3/0x240 fs/fs-writeback.c:2695
sync_filesystem+0x9f/0x220 fs/sync.c:54
generic_shutdown_super+0x6b/0x300 fs/super.c:448
kill_block_super+0x7c/0xe0 fs/super.c:1427
kill_f2fs_super+0x2ed/0x3a0 fs/f2fs/super.c:4565
deactivate_locked_super+0x93/0xf0 fs/super.c:335
cleanup_mnt+0x418/0x4d0 fs/namespace.c:1148
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+0xee/0x180 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: 0033:0x7f837e16e497
RSP: 002b:00007ffd195eed68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f837e1ee08c RCX: 00007f837e16e497
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd195eee20
RBP: 00007ffd195eee20 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd195efeb0
R13: 00007f837e1ee08c R14: 00000000000198c2 R15: 00007ffd195efef0
Showing all locks held in the system:
10 locks held by kworker/u4:0/9:
1 lock held by khungtaskd/27:
#0: ffffffff8c11c760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
6 locks held by kworker/u4:1/144:
4 locks held by kworker/u4:3/1197:
4 locks held by kworker/u4:4/1237:
2 locks held by getty/3950:
#0: ffff88802b8ad098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
4 locks held by kworker/u4:5/4322:
1 lock held by syz-executor/4829:
#0: ffff88807f26a0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5137:
#0: ffff8880722cc0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5164:
#0: ffff88807b5880e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5206:
#0: ffff88807e30c0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
3 locks held by kworker/u4:8/5221:
1 lock held by syz-executor/5235:
#0: ffff888058a0e0e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by syz-executor/5310:
#0: ffff88807d9040e0 (&type->s_umount_key#54){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365
1 lock held by udevd/5408:
#0: ffff88801faf6118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
2 locks held by syz.6.40/5418:
#0: ffff88801faf6118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
#1: ffff888147bec468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: writeback wb_workfn (flush-7:0)
RIP: 0010:__kasan_check_write+0x0/0x10 mm/kasan/shadow.c:37
Code: 8b eb 0a 48 c7 c7 cb 42 a3 8b 48 89 de e8 48 b9 e2 07 31 ed eb d7 00 00 cc cc 89 f6 48 8b 0c 24 31 d2 e9 43 ef ff ff 0f 1f 00 <89> f6 48 8b 0c 24 ba 01 00 00 00 e9 30 ef ff ff 55 41 56 53 48 89
RSP: 0018:ffffc90000ce6c18 EFLAGS: 00000256
RAX: ffff88813fed0001 RBX: ffff88805c8eac50 RCX: ffffffff815b4f0b
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffc90000ce6c60
RBP: ffffc90000ce6cd0 R08: dffffc0000000000 R09: ffffed100b91d58c
R10: ffffed100b91d58c R11: 1ffff1100b91d58b R12: 0000000000000001
R13: 1ffff1100b91d58b R14: ffff88813fed0000 R15: ffff88805c8eac58
FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc9ee7c3000 CR3: 000000001ddab000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
atomic_long_try_cmpxchg include/linux/atomic/atomic-instrumented.h:1660 [inline]
rwsem_clear_reader_owned kernel/locking/rwsem.c:213 [inline]
__up_read+0x1ea/0x660 kernel/locking/rwsem.c:1326
check_valid_map fs/f2fs/gc.c:884 [inline]
gc_data_segment fs/f2fs/gc.c:1451 [inline]
do_garbage_collect+0x1d13/0x60a0 fs/f2fs/gc.c:1671
f2fs_gc+0x8a9/0x1900 fs/f2fs/gc.c:1765
f2fs_balance_fs+0x491/0x660 fs/f2fs/segment.c:529
f2fs_write_inode+0x531/0x760 fs/f2fs/inode.c:745
write_inode fs/fs-writeback.c:1505 [inline]
__writeback_single_inode+0x6c3/0xda0 fs/fs-writeback.c:1715
writeback_sb_inodes+0x9fe/0x1610 fs/fs-writeback.c:1940
wb_writeback+0x443/0xb90 fs/fs-writeback.c:2114
wb_do_writeback fs/fs-writeback.c:2257 [inline]
wb_workfn+0x423/0xe60 fs/fs-writeback.c:2298
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