INFO: task udevd:6309 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:25008 pid:6309  ppid:3637   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5246 [inline]
 __schedule+0x107f/0x4030 kernel/sched/core.c:6563
 schedule+0xb9/0x180 kernel/sched/core.c:6639
 io_schedule+0x7c/0xd0 kernel/sched/core.c:8799
 folio_wait_bit_common+0x877/0xfa0 mm/filemap.c:1324
 folio_put_wait_locked mm/filemap.c:1493 [inline]
 do_read_cache_folio+0x1a7/0x790 mm/filemap.c:3641
 read_mapping_folio include/linux/pagemap.h:799 [inline]
 read_part_sector+0xce/0x360 block/partitions/core.c:724
 adfspart_check_POWERTEC+0xc0/0x890 block/partitions/acorn.c:454
 check_partition block/partitions/core.c:146 [inline]
 blk_add_partitions block/partitions/core.c:609 [inline]
 bdev_disk_changed+0x7f9/0x1450 block/partitions/core.c:695
 blkdev_get_whole+0x2e8/0x370 block/bdev.c:700
 blkdev_get_by_dev+0x32e/0xa60 block/bdev.c:837
 blkdev_open+0x119/0x2d0 block/fops.c:500
 do_dentry_open+0x7dd/0x10b0 fs/open.c:882
 do_open fs/namei.c:3677 [inline]
 path_openat+0x2674/0x2f10 fs/namei.c:3834
 do_filp_open+0x1ee/0x420 fs/namei.c:3861
 do_sys_openat2+0x14b/0x4f0 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1347
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc01e8a7407
RSP: 002b:00007fff5312f5b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc01eff4880 RCX: 00007fc01e8a7407
RDX: 00000000000a0800 RSI: 000055efbb835520 RDI: ffffffffffffff9c
RBP: 000055efbb81e910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055efbb833830
R13: 000055efbb836410 R14: 0000000000000000 R15: 000055efbb833830
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8d92e230 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8d92ea50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xef0 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
 #0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d92d8a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6669
2 locks held by getty/4025:
 #0: ffff88814d5d9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41e/0x1360 drivers/tty/n_tty.c:2198
1 lock held by udevd/6309:
 #0: ffff888144f354c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12a/0xa60 block/bdev.c:828
1 lock held by udevd/6602:
 #0: ffff888025e9b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12a/0xa60 block/bdev.c:828
1 lock held by udevd/6603:
 #0: ffff888144b804c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x12a/0xa60 block/bdev.c:828
1 lock held by syz-executor/10023:
1 lock held by dhcpcd-run-hook/10575:

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3e6/0x460 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xf0e/0xf50 kernel/hung_task.c:377
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 10571 Comm: syz.8.1700 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:separate_irq_context kernel/locking/lockdep.c:4642 [inline]
RIP: 0010:__lock_acquire+0xf4e/0x7ea0 kernel/locking/lockdep.c:5155
Code: 48 c1 e8 03 42 80 3c 00 00 74 12 48 89 df e8 b9 8e 6f 00 49 b8 00 00 00 00 00 fc ff df 4c 89 3b 48 8b 44 24 78 42 0f b6 04 00 <84> c0 0f 85 97 0d 00 00 48 8b 44 24 38 8b 18 48 85 db 74 5d 83 fb
RSP: 0018:ffffc9000488f340 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880212e28e0 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff91934240
RBP: ffffc9000488f588 R08: dffffc0000000000 R09: 1ffffffff2326848
R10: dffffc0000000000 R11: fffffbfff2326849 R12: 0000000000000000
R13: ffff8880212e1e00 R14: ffff8880212e28d0 R15: ffffffffffffffff
FS:  00007f4c3d5156c0(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000004000 CR3: 0000000029277000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 lock_acquire+0x1bc/0x4a0 kernel/locking/lockdep.c:5790
 _raw_spin_lock_nested+0x2e/0x40 kernel/locking/spinlock.c:378
 raw_spin_rq_lock_nested+0x98/0x130 kernel/sched/core.c:546
 raw_spin_rq_lock kernel/sched/sched.h:1362 [inline]
 rq_lock kernel/sched/sched.h:1652 [inline]
 __schedule+0x2d4/0x4030 kernel/sched/core.c:6479
 schedule+0xb9/0x180 kernel/sched/core.c:6639
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
 snd_rawmidi_write+0x3b6/0xb90 sound/core/rawmidi.c:1605
 do_loop_readv_writev fs/read_write.c:-1 [inline]
 do_iter_write+0x4a4/0xb10 fs/read_write.c:863
 vfs_writev fs/read_write.c:934 [inline]
 do_writev+0x27b/0x480 fs/read_write.c:977
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4c3c59e1d9
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:00007f4c3d515028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007f4c3c825fa0 RCX: 00007f4c3c59e1d9
RDX: 0000000000000002 RSI: 0000200000000840 RDI: 0000000000000004
RBP: 00007f4c3c635888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4c3c826038 R14: 00007f4c3c825fa0 R15: 00007fff8b7e16d8
 </TASK>