INFO: task udevd:6398 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:24968 pid:6398  ppid:5157   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 io_schedule+0x80/0xd0 kernel/sched/core.c:9022
 folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329
 folio_put_wait_locked mm/filemap.c:1493 [inline]
 do_read_cache_folio+0x1c0/0x7e0 mm/filemap.c:3771
 read_mapping_folio include/linux/pagemap.h:898 [inline]
 read_part_sector+0xd2/0x350 block/partitions/core.c:718
 adfspart_check_POWERTEC+0x8d/0xf00 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+0x73a/0x1410 block/partitions/core.c:689
 blkdev_get_whole+0x30d/0x390 block/bdev.c:655
 blkdev_get_by_dev+0x279/0x600 block/bdev.c:797
 blkdev_open+0x152/0x360 block/fops.c:589
 do_dentry_open+0x8c6/0x1500 fs/open.c:929
 do_open fs/namei.c:3632 [inline]
 path_openat+0x274b/0x3190 fs/namei.c:3789
 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
 do_sys_open fs/open.c:1434 [inline]
 __do_sys_openat fs/open.c:1450 [inline]
 __se_sys_openat fs/open.c:1445 [inline]
 __x64_sys_openat+0x139/0x160 fs/open.c:1445
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd53aaa7407
RSP: 002b:00007ffd84905fb0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd53b190880 RCX: 00007fd53aaa7407
RDX: 0000000000080000 RSI: 0000562d3584ff90 RDI: ffffffffffffff9c
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000562d0564695f
R13: 0000562d05657660 R14: 0000000000000000 R15: 00000000ffffffff
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
4 locks held by kworker/u4:3/48:
 #0: ffff88801a27e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff88801a27e938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc90000b97d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc90000b97d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff88814d9060e0 (&type->s_umount_key#31){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
 #3: ffff88814d910bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1767 [inline]
 #3: ffff88814d910bd8 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x170/0x2f0 fs/ext4/inode.c:2806
2 locks held by kworker/u4:6/1127:
2 locks held by getty/5548:
 #0: ffff88802d6130a0 (&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+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by udevd/6398:
 #0: ffff8881413834c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788
6 locks held by kworker/0:8/11449:
 #0: ffff88814725ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff88814725ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc90003a77d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc90003a77d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff88802516c190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #2: ffff88802516c190 (&dev->mutex){....}-{3:3}, at: hub_event+0x185/0x49c0 drivers/usb/core/hub.c:5861
 #3: ffff888050160190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #3: ffff888050160190 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x400 drivers/base/dd.c:1005
 #4: ffff888069214160 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #4: ffff888069214160 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x400 drivers/base/dd.c:1005
 #5: ffff88806c221a20 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:992 [inline]
 #5: ffff88806c221a20 (&dev->mutex){....}-{3:3}, at: __device_attach+0x89/0x400 drivers/base/dd.c:1005
2 locks held by rm/13801:

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x39b/0x3d0 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+0xf41/0xf80 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 13802 Comm: dhcpcd-run-hook Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:19 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:check_preemption_disabled+0x4d/0x110 lib/smp_processor_id.c:19
Code: 58 95 75 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d c3 <48> c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 74 cc 65
RSP: 0018:ffffc9000c016fc0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000080000000
RDX: dffffc0000000000 RSI: ffffffff8aac0400 RDI: ffffffff8afc71c0
RBP: 0000000000000000 R08: ffffffff8e4a91af R09: 1ffffffff1c95235
R10: dffffc0000000000 R11: fffffbfff1c95236 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f547ce4c4e8 CR3: 000000005124f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ct_dynticks_nesting include/linux/context_tracking_state.h:80 [inline]
 rcu_irq_exit_check_preempt+0x63/0x210 kernel/rcu/tree.c:573
 raw_irqentry_exit_cond_resched+0x17/0x30 kernel/entry/common.c:391
 irqentry_exit+0x67/0x70 kernel/entry/common.c:438
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:unwind_next_frame+0x38/0x2970 arch/x86/kernel/unwind_orc.c:470
Code: 48 81 ec 98 00 00 00 49 89 fc 49 bd 00 00 00 00 00 fc ff df e8 b9 f4 4a 00 49 8d 5c 24 48 48 89 d8 48 c1 e8 03 48 89 44 24 40 <42> 80 3c 28 00 74 08 48 89 df e8 b9 3f a2 00 48 89 5c 24 20 4d 8b
RSP: 0018:ffffc9000c0170d8 EFLAGS: 00000a02
RAX: 1ffff92001802e3e RBX: ffffc9000c0171f0 RCX: ffff8880187c3c00
RDX: 0000000000000000 RSI: ffffffff8a6e00e5 RDI: ffffc9000c0171a8
RBP: ffffc9000c017230 R08: ffffc9000c017270 R09: 000000000000000c
R10: 0000000000000004 R11: 0000000000000000 R12: ffffc9000c0171a8
R13: dffffc0000000000 R14: ffffffff817474c0 R15: ffffc9000c0171a8
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767
 slab_alloc_node mm/slub.c:3495 [inline]
 slab_alloc mm/slub.c:3503 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3510 [inline]
 kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3519
 vma_lock_alloc kernel/fork.c:460 [inline]
 vm_area_dup+0x61/0x270 kernel/fork.c:513
 __split_vma+0x19f/0xc00 mm/mmap.c:2373
 do_vmi_align_munmap+0x377/0x1660 mm/mmap.c:2514
 do_vmi_munmap+0x252/0x2d0 mm/mmap.c:2660
 __mmap_region mm/mmap.c:2710 [inline]
 mmap_region+0x741/0x2020 mm/mmap.c:2941
 do_mmap+0x92f/0x10a0 mm/mmap.c:1385
 vm_mmap_pgoff+0x1c0/0x400 mm/util.c:556
 ksys_mmap_pgoff+0x520/0x700 mm/mmap.c:1431
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f547ce75242
Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00
RSP: 002b:00007fff8cc82598 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f547cd25000 RCX: 00007f547ce75242
RDX: 0000000000000001 RSI: 0000000000057000 RDI: 00007f547cd25000
RBP: 0000000000000812 R08: 0000000000000003 R09: 0000000000176000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007fff8cc82620
R13: 00007f547ce515f0 R14: 00007fff8cc82dd0 R15: 00000ffff19904b6
 </TASK>