INFO: task syz-executor:5865 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:21432 pid:5865 tgid:5865 ppid:1 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
io_schedule+0x80/0xd0 kernel/sched/core.c:7789
folio_wait_bit_common+0x6b0/0xb80 mm/filemap.c:1323
__folio_lock mm/filemap.c:1699 [inline]
folio_lock include/linux/pagemap.h:1159 [inline]
__filemap_get_folio_mpol+0x13e/0xb00 mm/filemap.c:1954
__filemap_get_folio include/linux/pagemap.h:763 [inline]
truncate_inode_pages_range+0x3f0/0xd90 mm/truncate.c:413
evict+0x607/0xae0 fs/inode.c:839
dispose_list fs/inode.c:879 [inline]
evict_inodes+0x753/0x7e0 fs/inode.c:933
generic_shutdown_super+0x9a/0x2c0 fs/super.c:628
kill_block_super+0x44/0x90 fs/super.c:1722
deactivate_locked_super+0xbc/0x130 fs/super.c:474
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
task_work_run+0x1d4/0x260 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa8c1990a77
RSP: 002b:00007ffcfc17a5a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fa8c1a13d7d RCX: 00007fa8c1990a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffcfc17a660
RBP: 00007ffcfc17a660 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffcfc17b6f0
R13: 00007fa8c1a13d7d R14: 00000000000ae2f3 R15: 00007ffcfc17b730
Showing all locks held in the system:
2 locks held by rcu_tasks_trace/29:
#0: ffffffff8df42730 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0xaf9/0xdf0 kernel/rcu/tasks.h:614
#1: ffff8880b873a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
1 lock held by khungtaskd/32:
#0:
ffffffff8df419e0
(
rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5581:
#0: ffff88814da230a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5865:
#0: ffff88803dd7c0e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88803dd7c0e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88803dd7c0e0 (&type->s_umount_key#90){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
4 locks held by udevd/6288:
#0: ffff8880242079e0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182
#1: ffff8880568c2088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172
#2: ffffffff998de508 (&____s->seqcount#2){----}-{0:0}, at: ktime_get+0x45/0x200 kernel/time/timekeeping.c:824
#3: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: read_seqbegin_or_lock include/linux/seqlock.h:1130 [inline]
#3: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: prepend_path+0x22a/0x830 fs/d_path.c:171
1 lock held by syz.7.8009/24694:
#0: ffff88803dd7c0e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff88803dd7c0e0 (&type->s_umount_key#90){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
1 lock held by syz.7.8009/24696:
#0: ffff88803dd7c0e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff88803dd7c0e0 (&type->s_umount_key#90){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
4 locks held by syz.1.8938/26791:
#0: ffffffff8f274748 (register_mutex#4){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#0: ffffffff8f274748 (register_mutex#4){+.+.}-{4:4}, at: odev_release+0x46/0xa0 sound/core/seq/oss/seq_oss.c:140
#1: ffff88807c1528b8 (&mdev->open_mutex){+.+.}-{4:4}, at: class_mutex_constructor include/linux/mutex.h:253 [inline]
#1: ffff88807c1528b8 (&mdev->open_mutex){+.+.}-{4:4}, at: snd_seq_oss_midi_close+0x1c8/0x6f0 sound/core/seq/oss/seq_oss_midi.c:373
#2: ffff88807afe11f0 (&grp->list_mutex){++++}-{4:4}, at: class_rwsem_write_constructor include/linux/rwsem.h:257 [inline]
#2: ffff88807afe11f0 (&grp->list_mutex){++++}-{4:4}, at: snd_seq_port_disconnect+0x54/0x690 sound/core/seq/seq_ports.c:623
#3: ffff8880b873a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 32 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17135 Comm: kworker/1:14 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 ce 9e a6 fc 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 bf f0 0c fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 f5 2e f5 fb cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90004c46e10 EFLAGS: 00000002
RAX: 1ffffffff337de00 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000002a7e RDI: 0000000000002a7f
RBP: ffffffff99bef510 R08: ffff8881405e8237 R09: 1ffff110280bd046
R10: dffffc0000000000 R11: ffffffff851b1190 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff99bef280 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125f3a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33a1cff8 CR3: 0000000033126000 CR4: 0000000000350ef0
Call Trace:
serial_in drivers/tty/serial/8250/8250.h:128 [inline]
serial_lsr_in drivers/tty/serial/8250/8250.h:150 [inline]
wait_for_lsr+0x1a1/0x2f0 drivers/tty/serial/8250/8250_port.c:1961
fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline]
serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3342
console_emit_next_record kernel/printk/printk.c:3129 [inline]
console_flush_one_record kernel/printk/printk.c:3215 [inline]
console_flush_all+0x745/0xb60 kernel/printk/printk.c:3289
__console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
console_unlock+0xbb/0x190 kernel/printk/printk.c:3359
vprintk_emit+0x4f8/0x5f0 kernel/printk/printk.c:2426
dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914
dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925
_dev_info+0x10a/0x160 drivers/base/core.c:4983
usb_disconnect+0xdd/0x990 drivers/usb/core/hub.c:2327
hub_port_connect drivers/usb/core/hub.c:5407 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
port_event drivers/usb/core/hub.c:5871 [inline]
hub_event+0x1ca9/0x4ef0 drivers/usb/core/hub.c:5953
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246