INFO: task udevd:5995 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:21504 pid:5995 tgid:5995 ppid:5192 task_flags:0x400140 flags:0x00080802
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7008
io_schedule+0x7f/0xd0 kernel/sched/core.c:7835
folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323
folio_put_wait_locked mm/filemap.c:1492 [inline]
do_read_cache_folio+0x1ad/0x590 mm/filemap.c:4083
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:723
adfspart_check_POWERTEC+0x92/0xef0 block/partitions/acorn.c:454
check_partition block/partitions/core.c:142 [inline]
blk_add_partitions block/partitions/core.c:590 [inline]
bdev_disk_changed+0x7ba/0x1550 block/partitions/core.c:694
blkdev_get_whole+0x380/0x510 block/bdev.c:764
bdev_open+0x31e/0xd30 block/bdev.c:973
blkdev_open+0x470/0x610 block/fops.c:697
do_dentry_open+0x785/0x14e0 fs/open.c:949
vfs_open+0x3b/0x340 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4830
do_file_open+0x23e/0x4a0 fs/namei.c:4859
do_sys_openat2+0x113/0x200 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa536fce407
RSP: 002b:00007fff68ed4e50 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fa536f42880 RCX: 00007fa536fce407
RDX: 00000000000a0800 RSI: 0000564c29bbf150 RDI: ffffffffffffff9c
RBP: 0000564c29bad910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000564c29bd4fe0
R13: 0000564c29bbb190 R14: 0000000000000000 R15: 0000564c29bd4fe0
Showing all locks held in the system:
2 locks held by ksoftirqd/1/23:
#0: ffff8880b873ae60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647
#1: ffffffff9a2c0508 (&____s->seqcount#2){----}-{0:0}, at: ktime_get_real_ts64+0xa9/0x3c0 kernel/time/timekeeping.c:802
1 lock held by khungtaskd/31:
#0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e75e620 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by dhcpcd/5488:
2 locks held by getty/5584:
#0: ffff888036bca0a0 (&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+0x45c/0x13c0 drivers/tty/n_tty.c:2211
2 locks held by kworker/u9:5/5836:
#0: ffff888025a7b148 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff888025a7b148 ((wq_completion)nbd2-recv){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90004097c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90004097c40 ((work_completion)(&args->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
1 lock held by udevd/5880:
#0: ffff888026a84358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
1 lock held by udevd/5995:
#0: ffff888025a76358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961
5 locks held by kworker/u8:23/17156:
3 locks held by kworker/1:11/22854:
#0: ffff88813fe0f148 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88813fe0f148 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc9000e4cfc40 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc9000e4cfc40 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffffffff8e764800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by syz.3.5880/26985:
#0: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#0: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
3 locks held by syz.2.5879/26986:
#0: ffff888046aa7508 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#0: ffff888046aa7508 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline]
#0: ffff888046aa7508 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455
#1: ffff888086300260 (sk_lock-AF_CAN){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1709 [inline]
#1: ffff888086300260 (sk_lock-AF_CAN){+.+.}-{0:0}, at: isotp_release+0x46d/0xa80 net/can/isotp.c:1221
#2: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#2: ffffffff8e764938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
3 locks held by dhcpcd-run-hook/26992:
#0: ffff8880b873ae60 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647
#1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
#2: ffff888032328498 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline]
#2: ffff888032328498 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: pte_offset_map_lock+0x13d/0x210 mm/pgtable-generic.c:402
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [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+0xfd9/0x1030 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5833 Comm: kworker/u9:4 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: hci1 hci_cmd_timeout
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401
Code: e8 8e b3 84 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 0f fc ee fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f e9 8a fd 70 06 cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90003ab73f0 EFLAGS: 00000002
RAX: 1ffffffff34ba900 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020
RBP: ffffffff9a5d4c50 R08: ffff888025758237 R09: 1ffff11004aeb046
R10: dffffc0000000000 R11: ffffffff8540fa90 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9a5d49c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812545a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb30ebcd7e8 CR3: 000000007972c000 CR4: 00000000003526f0
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:1970
serial8250_fifo_wait_for_lsr_thre drivers/tty/serial/8250/8250_port.c:3207 [inline]
serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3272 [inline]
serial8250_console_write+0x1348/0x1ba0 drivers/tty/serial/8250/8250_port.c:3357
console_emit_next_record kernel/printk/printk.c:3183 [inline]
console_flush_one_record kernel/printk/printk.c:3269 [inline]
console_flush_all+0x718/0xb20 kernel/printk/printk.c:3343
__console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
_printk+0xdd/0x130 kernel/printk/printk.c:2504
bt_err+0x121/0x180 net/bluetooth/lib.c:296
hci_cmd_timeout+0xff/0x1e0 net/bluetooth/hci_core.c:1474
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245