INFO: task udevd:17494 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:23176 pid:17494 ppid:5141   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 io_schedule+0x80/0xd0 kernel/sched/core.c:9024
 folio_wait_bit_common+0x881/0xfa0 mm/filemap.c:1329
 folio_put_wait_locked mm/filemap.c:1493 [inline]
 do_read_cache_folio+0x1c0/0x7f0 mm/filemap.c:3791
 read_mapping_folio include/linux/pagemap.h:898 [inline]
 read_part_sector+0xd2/0x350 block/partitions/core.c:718
 adfspart_check_POWERTEC+0x93/0xed0 block/partitions/acorn.c:454
 check_partition block/partitions/core.c:138 [inline]
 blk_add_partitions block/partitions/core.c:600 [inline]
 bdev_disk_changed+0x755/0x1450 block/partitions/core.c:689
 blkdev_get_whole+0x30d/0x390 block/bdev.c:668
 blkdev_get_by_dev+0x3a9/0x610 block/bdev.c:810
 blkdev_open+0x14e/0x360 block/fops.c:589
 do_dentry_open+0x880/0x14b0 fs/open.c:929
 do_open fs/namei.c:3683 [inline]
 path_openat+0x284f/0x3270 fs/namei.c:3844
 do_filp_open+0x1f2/0x430 fs/namei.c:3871
 do_sys_openat2+0x134/0x1d0 fs/open.c:1422
 do_sys_open fs/open.c:1437 [inline]
 __do_sys_openat fs/open.c:1453 [inline]
 __se_sys_openat fs/open.c:1448 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1448
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5d240a7407
RSP: 002b:00007ffca85ec9f0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5d247b2880 RCX: 00007f5d240a7407
RDX: 00000000000a0800 RSI: 000055be251118e0 RDI: ffffffffffffff9c
RBP: 000055be25100910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055be25118e00
R13: 000055be25118410 R14: 0000000000000000 R15: 000055be25118e00
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5529:
 #0: ffff88802d7de0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
2 locks held by kworker/u4:15/6292:
 #0: ffff8880b8e3c298 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
 #1: ffffc9000ca5fd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000ca5fd00 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
2 locks held by kworker/u4:14/11766:
 #0: ffff888018efdd38 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888018efdd38 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000cd07d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000cd07d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
1 lock held by udevd/17494:
 #0: ffff88814172d4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by udevd/17526:
 #0: ffff888021e184c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by udevd/17528:
 #0: ffff888021fa34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by udevd/17741:
 #0: ffff888021fb34c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by udevd/18884:
 #0: ffff888141b804c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by udevd/19964:
 #0: ffff888021e364c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by udevd/32123:
 #0: ffff888141b184c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 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+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+0xf59/0xfa0 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
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5130 Comm: klogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:update_curr+0x3/0x810 kernel/sched/fair.c:1202
Code: 83 c5 80 e9 e6 fd ff ff 49 c7 c5 ff ff ff ff e9 2a ff ff ff 0f 0b e9 64 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 55 41 57 <41> 56 41 55 41 54 53 48 83 ec 38 48 89 fd 49 bd 00 00 00 00 00 fc
RSP: 0018:ffffc900032a7578 EFLAGS: 00000002
RAX: 0000000000000000 RBX: ffff8880b8f3c340 RCX: ffff88807d9b0001
RDX: ffffc900032a77b0 RSI: ffff88807d0a9e80 RDI: ffff8880b8f3c340
RBP: dffffc0000000000 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000654eac R12: ffff88807d9b0118
R13: 1ffff1100fa153d9 R14: ffff88807d0a9e80 R15: ffff88807d0a9ec8
FS:  00007f4c6d1e5c80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f07e887a6c8 CR3: 0000000030757000 CR4: 00000000003506e0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 put_prev_entity+0x3d/0x1f0 kernel/sched/fair.c:5510
 pick_next_task_fair+0x428/0x670 kernel/sched/fair.c:8514
 __pick_next_task kernel/sched/core.c:6007 [inline]
 pick_next_task kernel/sched/core.c:6082 [inline]
 __schedule+0x6ee/0x4660 kernel/sched/core.c:6663
 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6868
 preempt_schedule+0xc0/0xd0 kernel/sched/core.c:6892
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0x111/0x120 kernel/locking/spinlock.c:194
 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
 __wake_up_common_lock kernel/sched/wait.c:140 [inline]
 __wake_up_sync_key+0x12c/0x1a0 kernel/sched/wait.c:213
 sock_def_readable+0x1e1/0x420 net/core/sock.c:3362
 unix_dgram_sendmsg+0x1093/0x16e0 net/unix/af_unix.c:2143
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x4a9/0x6b0 net/socket.c:2201
 __do_sys_sendto net/socket.c:2213 [inline]
 __se_sys_sendto net/socket.c:2209 [inline]
 __x64_sys_sendto+0xde/0xf0 net/socket.c:2209
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4c6d335407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffde97bb970 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f4c6d1e5c80 RCX: 00007f4c6d335407
RDX: 000000000000008b RSI: 00007ffde97bbab0 RDI: 0000000000000003
RBP: 00007ffde97bbee0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffde97bbef8
R13: 00007ffde97bbab0 R14: 0000000000000070 R15: 00007ffde97bbab0
 </TASK>