INFO: task udevd:5633 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:25448 pid:5633  tgid:5633  ppid:4951   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x16dc/0x5500 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7326
 io_schedule+0x80/0xe0 kernel/sched/core.c:8154
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __wait_on_bit_lock+0xe0/0x4a0 kernel/sched/wait_bit.c:93
 out_of_line_wait_on_bit_lock+0x13b/0x190 kernel/sched/wait_bit.c:120
 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline]
 __lock_buffer fs/buffer.c:68 [inline]
 lock_buffer include/linux/buffer_head.h:434 [inline]
 block_read_full_folio+0x38f/0x810 fs/buffer.c:2417
 filemap_read_folio+0x12c/0x3a0 mm/filemap.c:2516
 filemap_update_page mm/filemap.c:2603 [inline]
 filemap_get_pages+0x16f9/0x1e80 mm/filemap.c:2733
 filemap_read+0x429/0x11e0 mm/filemap.c:2820
 blkdev_read_iter+0x2f8/0x430 block/fops.c:830
 new_sync_read fs/read_write.c:493 [inline]
 vfs_read+0x59e/0xa90 fs/read_write.c:574
 ksys_read+0x156/0x270 fs/read_write.c:716
 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: 0033:0x7f1804d9e407
RSP: 002b:00007ffe778d6610 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f1804cb0880 RCX: 00007f1804d9e407
RDX: 0000000000000200 RSI: 00007f1804361000 RDI: 0000000000000009
RBP: 000055806f80b050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000008000 R14: 000055806f81bb68 R15: 00007f18054f439c
 </TASK>

Showing all locks held in the system:
2 locks held by kworker/u8:1/13:
 #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #0: ffff88813ff5c138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
 #1: ffffc90000127c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline]
 #1: ffffc90000127c40 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405
1 lock held by khungtaskd/38:
 #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
 #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kswapd0/93:
2 locks held by getty/5337:
 #0: ffff8880363e30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
2 locks held by udevd/5627:
 #0: ffff88802360b108 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
 #0: ffff88802360b108 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2e6/0x430 block/fops.c:829
 #1: ffff88802360b2d8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1089 [inline]
 #1: ffff88802360b2d8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2569 [inline]
 #1: ffff88802360b2d8 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x936/0x1e80 mm/filemap.c:2733
2 locks held by udevd/5633:
 #0: ffff88802360be48 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
 #0: ffff88802360be48 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2e6/0x430 block/fops.c:829
 #1: ffff88802360c018 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1089 [inline]
 #1: ffff88802360c018 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2569 [inline]
 #1: ffff88802360c018 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x936/0x1e80 mm/filemap.c:2733
1 lock held by syz.0.17/5949:
2 locks held by udevd/5971:
 #0: ffff88802360a3c8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
 #0: ffff88802360a3c8 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2e6/0x430 block/fops.c:829
 #1: ffff88802360a598 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1089 [inline]
 #1: ffff88802360a598 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2569 [inline]
 #1: ffff88802360a598 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x936/0x1e80 mm/filemap.c:2733
2 locks held by syz.1.18/6005:
2 locks held by syz.2.19/6041:
2 locks held by udevd/6045:
 #0: ffff888023608948 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
 #0: ffff888023608948 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2e6/0x430 block/fops.c:829
 #1: ffff888023608b18 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1089 [inline]
 #1: ffff888023608b18 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2569 [inline]
 #1: ffff888023608b18 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x936/0x1e80 mm/filemap.c:2733
2 locks held by udevd/6048:
 #0: ffff888023609688 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
 #0: ffff888023609688 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2e6/0x430 block/fops.c:829
 #1: ffff888023609858 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1089 [inline]
 #1: ffff888023609858 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2569 [inline]
 #1: ffff888023609858 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x936/0x1e80 mm/filemap.c:2733
1 lock held by syz.3.20/6086:
2 locks held by syz.4.21/6128:
2 locks held by udevd/6134:
 #0: ffff8880235ef348 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1039 [inline]
 #0: ffff8880235ef348 (&sb->s_type->i_mutex_key#9){++++}-{4:4}, at: blkdev_read_iter+0x2e6/0x430 block/fops.c:829
 #1: ffff8880235ef518 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1089 [inline]
 #1: ffff8880235ef518 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2569 [inline]
 #1: ffff8880235ef518 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x936/0x1e80 mm/filemap.c:2733
5 locks held by syz.5.22/6178:
1 lock held by modprobe/6186:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
 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+0xfd7/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 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
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6128 Comm: syz.4.21 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_preemption_disabled+0xd/0xe0 lib/smp_processor_id.c:16
Code: 1c 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 65 8b 05 77 fd 59 07 <65> 8b 0d 6c fd 59 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d e9
RSP: 0000:ffffc90003cd6f50 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000202 RCX: 0000000000000046
RDX: 0000000000000001 RSI: ffffffff8daf10f5 RDI: ffffffff8bca5980
RBP: ffff888030d6ca30 R08: ffffc90003cd7cb0 R09: 0000000000000000
R10: ffffc90003cd70d8 R11: fffff5200079ae1d R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8e1c3000 R15: ffff888030d6be00
FS:  00005555722ab500(0000) GS:ffff888125c45000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f771fdb7e9c CR3: 0000000036d66000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
 lock_release+0x259/0x3c0 kernel/locking/lockdep.c:5891
 rcu_lock_release include/linux/rcupdate.h:310 [inline]
 rcu_read_unlock include/linux/rcupdate.h:871 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1183 [inline]
 unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 save_stack+0x124/0x230 mm/page_owner.c:165
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0x10e7/0x11c0 mm/page_alloc.c:2950
 __folio_put+0x30f/0x3c0 mm/swap.c:112
 folio_put include/linux/mm.h:2124 [inline]
 __filemap_get_folio_mpol+0x4e1/0xf50 mm/filemap.c:2031
 __filemap_get_folio include/linux/pagemap.h:761 [inline]
 grow_dev_folio fs/buffer.c:960 [inline]
 grow_buffers fs/buffer.c:1026 [inline]
 __getblk_slow fs/buffer.c:1044 [inline]
 bdev_getblk+0x1f4/0x6e0 fs/buffer.c:1439
 ext4_sb_breadahead_unmovable+0x6f/0xf0 fs/ext4/super.c:280
 __ext4_get_inode_loc+0xb03/0xf40 fs/ext4/inode.c:4974
 __ext4_get_inode_loc_noinmem fs/ext4/inode.c:5004 [inline]
 __ext4_iget+0x44e/0x45b0 fs/ext4/inode.c:5316
 __ext4_fill_super fs/ext4/super.c:5600 [inline]
 ext4_fill_super+0x4de1/0x65d0 fs/ext4/super.c:5828
 get_tree_bdev_flags+0x430/0x4f0 fs/super.c:1640
 vfs_get_tree+0x92/0x2a0 fs/super.c:1700
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3765 [inline]
 do_new_mount+0x319/0xdc0 fs/namespace.c:3841
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4367
 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: 0033:0x7fe250cef34a
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffd554bc128 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffd554bc1b0 RCX: 00007fe250cef34a
RDX: 0000200000000240 RSI: 0000200000000280 RDI: 00007ffd554bc170
RBP: 0000200000000240 R08: 00007ffd554bc1b0 R09: 0000000000800003
R10: 0000000000800003 R11: 0000000000000246 R12: 0000200000000280
R13: 00007ffd554bc170 R14: 000000000000025f R15: 0000200000000000
 </TASK>