INFO: task syz-executor:5768 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:21704 pid:5768 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: 0033:0x7fbd2f39c629
RSP: 002b:00007ffe5e53ec48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fbd2f431f50 RCX: 00007fbd2f39c629
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 000000000000000c R08: 0000000000000000 R09: 00007fbd2f431ef0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe5e53ff00
R13: 00007fbd2f431ef0 R14: 00005555770744e8 R15: 00007ffe5e540fd0
Showing all locks held in the system:
2 locks held by kworker/u4:0/11:
2 locks held by kworker/u4:1/12:
#0: ffff88801a67f538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff88801a67f538 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90000117d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
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 getty/5526:
#0: ffff8880317920a0 (&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/5768:
#0: ffff88807a0140e0 (&type->s_umount_key#62){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
#0: ffff88807a0140e0 (&type->s_umount_key#62){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
#0: ffff88807a0140e0 (&type->s_umount_key#62){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
#1: ffff888021bcc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline]
#1: ffff888021bcc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x1ad/0xa10 fs/fs-writeback.c:2776
1 lock held by syz-executor/5770:
#0: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#0: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
2 locks held by kworker/1:3/5774:
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
#1: ffffc9000453fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000453fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711
3 locks held by segctord/5892:
4 locks held by kvm-nx-lpage-re/8646:
#0: ffffffff8d15ba08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:369 [inline]
#0: ffffffff8d15ba08 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_attach_task_all+0x26/0xe0 kernel/cgroup/cgroup-v1.c:61
#1: ffffffff8cfcd210 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock+0x11/0x30 kernel/cgroup/cgroup.c:2414
#2: ffffffff8d15bbf0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_task_all+0x30/0xe0 kernel/cgroup/cgroup-v1.c:62
#3: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
#3: ffffffff8d137978 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x306/0x880 kernel/rcu/tree_exp.h:1004
1 lock held by cmp/8661:
=============================================
NMI backtrace for cpu 1
CPU: 1 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 1172 Comm: kworker/0:1H Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: kblockd blk_mq_requeue_work
RIP: 0010:unwind_next_frame+0x15f/0x2970 arch/x86/kernel/unwind_orc.c:494
Code: 4b 00 4c 89 7c 24 78 4d 8d 74 24 35 4c 89 f0 48 c1 e8 03 48 89 44 24 38 42 0f b6 04 28 84 c0 48 8b 5c 24 20 0f 85 64 21 00 00 <45> 0f b6 3e 48 8b 44 24 40 42 80 3c 28 00 74 08 48 89 df e8 09 0d
RSP: 0018:ffffc900048eef18 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffffc900048ef030 RCX: ffff8880243b3c00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc900048ef038 R08: ffffc900048ef0b0 R09: 0000000000000002
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc900048eefe8
R13: dffffc0000000000 R14: ffffc900048ef01d R15: ffffffff815857ad
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd7d5642e9c CR3: 0000000060b74000 CR4: 00000000003526f0
Call Trace:
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
insert_work+0x3d/0x310 kernel/workqueue.c:1651
__queue_work+0xc39/0x1020 kernel/workqueue.c:1800
queue_work_on+0x128/0x1f0 kernel/workqueue.c:1835
queue_work include/linux/workqueue.h:562 [inline]
loop_queue_work drivers/block/loop.c:893 [inline]
loop_queue_rq+0x9d5/0xac0 drivers/block/loop.c:1900
blk_mq_dispatch_rq_list+0xdc6/0x1ea0 block/blk-mq.c:2084
__blk_mq_sched_dispatch_requests+0x36f/0x16e0 block/blk-mq-sched.c:301
blk_mq_sched_dispatch_requests+0xfb/0x1b0 block/blk-mq-sched.c:333
blk_mq_run_hw_queue+0x3f9/0x4e0 block/blk-mq.c:2330
blk_mq_run_hw_queues+0x34b/0x440 block/blk-mq.c:2379
blk_mq_requeue_work+0x7a9/0x800 block/blk-mq.c:1504
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
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