INFO: task udevd:5822 blocked in I/O wait 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:22088 pid:5822 tgid:5822 ppid:5001 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
io_schedule+0x7f/0xd0 kernel/sched/core.c:8110
folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1324
folio_put_wait_locked mm/filemap.c:1493 [inline]
do_read_cache_folio+0x1ad/0x590 mm/filemap.c:4089
read_mapping_folio include/linux/pagemap.h:1017 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
adfspart_check_POWERTEC+0x9a/0x7a0 block/partitions/acorn.c:450
check_partition block/partitions/core.c:143 [inline]
blk_add_partitions block/partitions/core.c:591 [inline]
bdev_disk_changed+0x817/0x1770 block/partitions/core.c:695
blkdev_get_whole+0x380/0x510 block/bdev.c:756
bdev_open+0x31e/0xd30 block/bdev.c:965
blkdev_open+0x470/0x610 block/fops.c:697
do_dentry_open+0x822/0x13a0 fs/open.c:947
vfs_open+0x3b/0x340 fs/open.c:1079
do_open fs/namei.c:4699 [inline]
path_openat+0x2e08/0x3860 fs/namei.c:4858
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd8ed8a7407
RSP: 002b:00007ffc0ae67e10 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd8ee05e880 RCX: 00007fd8ed8a7407
RDX: 00000000000a0800 RSI: 000055d2ef641320 RDI: ffffffffffffff9c
RBP: 000055d2ef624910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055d2ef6ca560
R13: 000055d2ef632190 R14: 0000000000000000 R15: 000055d2ef6ca560
Showing all locks held in the system:
3 locks held by kworker/u8:1/13:
#0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90000127c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90000127c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
1 lock held by khungtaskd/31:
#0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by udevd/5001:
#0: ffff8880b873aee0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:652
#1: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#1: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: trace_call_bpf+0xc2/0xb70 kernel/trace/bpf_trace.c:-1
2 locks held by getty/5387:
#0: ffff888032a840a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5617:
#0: ffff8880b873aee0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:652
1 lock held by udevd/5822:
#0: ffff888027721350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953
4 locks held by kworker/0:17/7839:
#0: ffff88801aeaed40 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801aeaed40 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc900038afc40 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc900038afc40 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8e9bcf28 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: srcu_advance_state kernel/rcu/srcutree.c:1813 [inline]
#2: ffffffff8e9bcf28 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: process_srcu+0x6e/0x1650 kernel/rcu/srcutree.c:1973
#3: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
#3: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
2 locks held by syz.4.2735/16617:
#0: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3438
#1: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.7.2739/16631:
#0: ffffffff8e9ce660 (event_mutex){+.+.}-{4:4}, at: perf_trace_destroy+0x2e/0x150 kernel/trace/trace_event_perf.c:239
1 lock held by syz.7.2740/16633:
#0: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150 net/core/dev_ioctl.c:815
2 locks held by syz.7.2740/16634:
#0: ffffffff8fda92c0 (br_ioctl_mutex){+.+.}-{4:4}, at: br_ioctl_call net/socket.c:1284 [inline]
#0: ffffffff8fda92c0 (br_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x4fa/0x7f0 net/socket.c:1388
#1: ffffffff8fdc8600 (rtnl_mutex){+.+.}-{4:4}, at: br_ioctl_stub+0x1a8/0xd60 net/bridge/br_ioctl.c:418
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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:162 [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:353 [inline]
watchdog+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 16633 Comm: syz.7.2740 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:401
Code: e8 4e 56 80 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 ff 4e ec fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc900045bf2b0 EFLAGS: 00000002
RAX: 1ffffffff34f2500 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 000000000004628f RDI: 0000000000046290
RBP: ffffffff9a792d10 R08: ffff888143ac8237 R09: 1ffff11028759046
R10: dffffc0000000000 R11: ffffffff85456cb0 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff9a792a80 R15: 0000000000000000
FS: 00007f7b653f76c0(0000) GS:ffff88812539a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff8d629f00 CR3: 00000000882d4000 CR4: 00000000003526f0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
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
br_set_state+0x493/0x730 net/bridge/br_stp.c:57
br_stp_disable_port+0x76/0x1d0 net/bridge/br_stp_if.c:106
br_stp_disable_bridge+0x81/0x150 net/bridge/br_stp_if.c:76
br_dev_stop+0x2d/0x180 net/bridge/br_device.c:193
__dev_close_many+0x36d/0x6e0 net/core/dev.c:1776
__dev_close net/core/dev.c:1788 [inline]
__dev_change_flags+0x3c1/0x7e0 net/core/dev.c:9756
netif_change_flags+0x88/0x1a0 net/core/dev.c:9821
dev_change_flags+0x130/0x270 net/core/dev_api.c:68
dev_ioctl+0x7b4/0x1150 net/core/dev_ioctl.c:816
sock_do_ioctl+0x23e/0x320 net/socket.c:1327
sock_ioctl+0x5c6/0x7f0 net/socket.c:1434
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7b6459ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f7b653f7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f7b64815fa0 RCX: 00007f7b6459ce59
RDX: 0000200000000900 RSI: 0000000000008914 RDI: 0000000000000005
RBP: 00007f7b64632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7b64816038 R14: 00007f7b64815fa0 R15: 00007fff8d62a1d8
----------------
Code disassembly (best guess):
0: e8 4e 56 80 fc call 0xfc805653
5: 44 89 f9 mov %r15d,%ecx
8: d3 e3 shl %cl,%ebx
a: 49 83 c6 40 add $0x40,%r14
e: 4c 89 f0 mov %r14,%rax
11: 48 c1 e8 03 shr $0x3,%rax
15: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
1a: 74 08 je 0x24
1c: 4c 89 f7 mov %r14,%rdi
1f: e8 ff 4e ec fc call 0xfcec4f23
24: 41 03 1e add (%r14),%ebx
27: 89 da mov %ebx,%edx
29: ec in (%dx),%al
* 2a: 0f b6 c0 movzbl %al,%eax <-- trapping instruction
2d: 5b pop %rbx
2e: 41 5c pop %r12
30: 41 5e pop %r14
32: 41 5f pop %r15
34: c3 ret
35: cc int3
36: cc int3
37: cc int3
38: cc int3
39: cc int3
3a: 44 89 f9 mov %r15d,%ecx
3d: 80 e1 07 and $0x7,%cl