INFO: task syz-executor:5774 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:21608 pid:5774 ppid:1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
wb_wait_for_completion+0x173/0x2a0 fs/fs-writeback.c:192
sync_inodes_sb+0x1c9/0xa10 fs/fs-writeback.c:2778
sync_filesystem+0x171/0x220 fs/sync.c:64
generic_shutdown_super+0x6f/0x2b0 fs/super.c:666
kill_block_super+0x44/0x90 fs/super.c:1660
deactivate_locked_super+0x97/0x100 fs/super.c:481
cleanup_mnt+0x43b/0x4d0 fs/namespace.c:1259
task_work_run+0x1d4/0x260 kernel/task_work.c:245
exit_task_work include/linux/task_work.h:43 [inline]
do_exit+0x95a/0x2460 kernel/exit.c:883
do_group_exit+0x21b/0x2d0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb4fc19c629
RSP: 002b:00007ffe8426db68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fb4fc231f50 RCX: 00007fb4fc19c629
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 000000000000000c R08: 0000000000000000 R09: 00007fb4fc231ef0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe8426ee20
R13: 00007fb4fc231ef0 R14: 00005555586c74e8 R15: 00007ffe8426fef0
Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131fa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:10/3472:
#0: ffff888018ea4538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888018ea4538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#1: ffffc9000c9d7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000c9d7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
2 locks held by getty/5533:
#0: ffff88814c8d90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217
2 locks held by syz-executor/5774:
#0: ffff8880294960e0 (&type->s_umount_key#74){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff8880294960e0 (&type->s_umount_key#74){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff8880294960e0 (&type->s_umount_key#74){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
#1: ffff888140f767d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff888140f767d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2776
4 locks held by kworker/u4:17/6819:
#0: ffff888018ea4538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888018ea4538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#1: ffffc900047efd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900047efd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#2: ffff88814de580e0 (&type->s_umount_key#31){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
#3: ffff88814de5abd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1767 [inline]
#3: ffff88814de5abd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x1a4/0x350 fs/ext4/inode.c:2806
2 locks held by syz.3.832/8910:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf3d/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6173 Comm: segctord Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:240 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4798 [inline]
RIP: 0010:__lock_acquire+0x969/0x7d40 kernel/locking/lockdep.c:5087
Code: 41 81 e6 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 00 f5 1b 91 be 08 00 00 00 e8 41 17 77 00 4c 0f a3 35 d9 c5 b3 0f 73 1a <49> 69 c6 d0 00 00 00 4c 8d b0 c0 73 b2 90 49 b8 00 00 00 00 00 fc
RSP: 0018:ffffc90004fbf700 EFLAGS: 00000057
RAX: 0000000000000101 RBX: 0000000000000001 RCX: ffffffff81682f1f
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911bf650
RBP: ffffc90004fbf948 R08: ffffffff911bf657 R09: 1ffffffff2237eca
R10: dffffc0000000000 R11: fffffbfff2237ecb R12: 0000000000000003
R13: ffff888028ce4728 R14: 0000000000000a88 R15: ffff888028ce4728
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb1799e82f8 CR3: 000000005de16000 CR4: 00000000003506e0
Call Trace:
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
_raw_spin_lock_nested+0x32/0x50 kernel/locking/spinlock.c:378
raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559
raw_spin_rq_lock kernel/sched/sched.h:1379 [inline]
rq_lock kernel/sched/sched.h:1688 [inline]
ttwu_queue kernel/sched/core.c:4026 [inline]
try_to_wake_up+0x609/0x1190 kernel/sched/core.c:4349
nilfs_segctor_wakeup+0x20c/0x330 fs/nilfs2/segment.c:2278
nilfs_segctor_notify fs/nilfs2/segment.c:2422 [inline]
nilfs_segctor_construct+0x472/0x690 fs/nilfs2/segment.c:2474
nilfs_segctor_thread_construct fs/nilfs2/segment.c:2562 [inline]
nilfs_segctor_thread+0x536/0x10d0 fs/nilfs2/segment.c:2646
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
vkms_vblank_simulate: vblank timer overrun