INFO: task udevd:4175 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:25792 pid: 4175 ppid:  3559 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 __mutex_lock_common+0xc71/0x2390 kernel/locking/mutex.c:669
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743
 device_lock include/linux/device.h:764 [inline]
 uevent_show+0x17a/0x330 drivers/base/core.c:2408
 dev_attr_show+0x50/0xb0 drivers/base/core.c:2110
 sysfs_kf_seq_show+0x316/0x4c0 fs/sysfs/file.c:61
 seq_read_iter+0x49b/0xd50 fs/seq_file.c:230
 call_read_iter include/linux/fs.h:2167 [inline]
 new_sync_read fs/read_write.c:404 [inline]
 vfs_read+0x725/0xcf0 fs/read_write.c:485
 ksys_read+0x14d/0x250 fs/read_write.c:623
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f17eee40407
RSP: 002b:00007ffdaef8cd30 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f17eed52880 RCX: 00007f17eee40407
RDX: 0000000000001000 RSI: 00005614137d6a00 RDI: 0000000000000008
RBP: 00007f17eef88ff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000000000000000a
R13: 00007f17eef88ea0 R14: 0000000000000000 R15: 000056141381c0a0
 </TASK>

Showing all locks held in the system:
2 locks held by init/1:
 #0: ffff88802b8e7128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88802b8e7128 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
7 locks held by kworker/u4:4/1645:
2 locks held by klogd/3548:
 #0: ffff88807ee76a28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807ee76a28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298
 #1: ffffffff8c1dc3e8 (pcpu_drain_mutex){+.+.}-{3:3}, at: __drain_all_pages+0x57/0x720 mm/page_alloc.c:3189
2 locks held by udevd/3559:
 #0: ffff88807dd56328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88807dd56328 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114
2 locks held by crond/3926:
2 locks held by getty/3943:
 #0: ffff88802c219098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
4 locks held by syz-executor/4170:
3 locks held by udevd/4173:
 #0: ffff88807ac4b1c8 (&tsk->futex_exit_mutex){+.+.}-{3:3}, at: futex_cleanup_begin kernel/futex/core.c:3893 [inline]
 #0: ffff88807ac4b1c8 (&tsk->futex_exit_mutex){+.+.}-{3:3}, at: futex_exit_release+0x2f/0x1c0 kernel/futex/core.c:3945
 #1: ffff88807b5a4028 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #1: ffff88807b5a4028 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298
 #2: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 #2: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 #2: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114
4 locks held by udevd/4175:
 #0: ffff888219db3668 (&p->lock){+.+.}-{3:3}, at: seq_read_iter+0xad/0xd50 fs/seq_file.c:182
 #1: ffff8880799be488 (&of->mutex){+.+.}-{3:3}, at: kernfs_seq_start+0x51/0x3c0 fs/kernfs/file.c:112
 #2: ffff888219db4e88 (kn->active#32){++++}-{0:0}, at: kernfs_seq_start+0x71/0x3c0 fs/kernfs/file.c:113
 #3: ffff88807eb491a8 (&dev->mutex
){....}-{3:3}
, at: device_lock include/linux/device.h:764 [inline]
, at: uevent_show+0x17a/0x330 drivers/base/core.c:2408
3 locks held by udevd/4200:
 #0: ffff88801ab94f88 (&tsk->futex_exit_mutex){+.+.}-{3:3}, at: futex_cleanup_begin kernel/futex/core.c:3893 [inline]
 #0: ffff88801ab94f88 (&tsk->futex_exit_mutex){+.+.}-{3:3}, at: futex_exit_release+0x2f/0x1c0 kernel/futex/core.c:3945
 #1: ffff888025f70128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #1: ffff888025f70128 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298
 #2: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 #2: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 #2: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114
3 locks held by kworker/0:4/4244:
3 locks held by kworker/u4:5/4274:
2 locks held by udevd/4331:
 #0: ffff88801eba5c28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88801eba5c28 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298
 #1: ffffffff8c1dc6e0
 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114
3 locks held by kworker/u4:6/4379:
4 locks held by udevd/4477:
2 locks held by kworker/0:10/4788:
3 locks held by syz.3.134/4947:
 #0: ffff88814797cd48 (&q->debugfs_mutex){+.+.}-{3:3}, at: blk_trace_setup+0xac/0x1d0 kernel/trace/blktrace.c:616
 #1: ffffffff8c15ae28 (relay_channels_mutex){+.+.}-{3:3}, at: relay_open+0x314/0x8e0 kernel/relay.c:518
 #2: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 #2: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 #2: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114
6 locks held by kworker/0:16/5625:
 #0: ffff8881415ab138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
 #1: ffffc9000552fd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
 #2: ffff888148414220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
 #2: ffff888148414220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1a7/0x5560 drivers/usb/core/hub.c:5827
 #3: ffff88807616e220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
 #3: ffff88807616e220 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:954
 #4: ffff88807eb491a8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:764 [inline]
 #4: ffff88807eb491a8 (&dev->mutex){....}-{3:3}, at: __device_attach+0x85/0x460 drivers/base/dd.c:954
 #5: ffffffff8bfccf90 (umhelper_sem){++++}-{3:3}, at: usermodehelper_read_trylock+0xe7/0x320 kernel/umh.c:217
2 locks held by syz-executor/6388:
 #0: ffff88802b6f1628 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
 #0: ffff88802b6f1628 (&mm->mmap_lock){++++}-{3:3}, at: do_user_addr_fault+0x2b9/0xc80 arch/x86/mm/fault.c:1298
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114
2 locks held by syz-executor/6394:
 #0: ffff88802b6f2b28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff88802b6f2b28 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:549
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114
2 locks held by syz-executor/6397:
 #0: ffff888025f71d28 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff888025f71d28 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:549
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114
2 locks held by syz-executor/6398:
 #0: ffff888025f77128 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff888025f77128 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:549
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114
2 locks held by syz-executor/6399:
 #0: ffff888025f76328 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff888025f76328 (&mm->mmap_lock){++++}-{3:3}, at: vm_mmap_pgoff+0x15d/0x2b0 mm/util.c:549
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114
2 locks held by dhcpcd-run-hook/6400:
 #0: ffff88801ce74b58 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:842 [inline]
 #0: ffff88801ce74b58 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_fault+0x84b/0x13b0 mm/filemap.c:3096
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __perform_reclaim mm/page_alloc.c:4654 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 #1: ffffffff8c1dc6e0 (fs_reclaim){+.+.}-{0:0}, at: __alloc_pages_slowpath+0x1056/0x27a0 mm/page_alloc.c:5114

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6388 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:rcu_read_lock include/linux/rcupdate.h:741 [inline]
RIP: 0010:list_lru_count_one+0x49/0x310 mm/list_lru.c:181
Code: 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 ff e8 9b 5f 12 00 48 63 db 48 c1 e3 07 49 03 1f e8 1c 87 ba ff e8 57 2e 00 00 <e8> d2 17 f8 07 89 c5 31 ff 89 c6 e8 37 fa cd ff 85 ed 74 18 e8 ee
RSP: 0000:ffffc90002ecec28 EFLAGS: 00000292
RAX: 4ac7fd6a080cca00 RBX: ffff8880168c6e00 RCX: 4ac7fd6a080cca00
RDX: 0000000000000000 RSI: ffffffff8a0b2e80 RDI: ffffffff8a59e800
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1ff5419
R10: fffffbfff1ff5419 R11: 1ffffffff1ff5418 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888016a7c000 R15: ffff8880169e6818
FS:  000055557dd72500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f17eed52b60 CR3: 000000007c644000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 list_lru_shrink_count include/linux/list_lru.h:123 [inline]
 super_cache_count+0x187/0x290 fs/super.c:148
 do_shrink_slab+0x8d/0xd00 mm/vmscan.c:712
 shrink_slab+0x1b1/0x770 mm/vmscan.c:925
 shrink_node_memcgs mm/vmscan.c:2958 [inline]
 shrink_node+0x110c/0x2610 mm/vmscan.c:3079
 shrink_zones mm/vmscan.c:3285 [inline]
 do_try_to_free_pages+0x5da/0x15c0 mm/vmscan.c:3340
 try_to_free_pages+0x8ef/0xdc0 mm/vmscan.c:3575
 __perform_reclaim mm/page_alloc.c:4657 [inline]
 __alloc_pages_direct_reclaim mm/page_alloc.c:4678 [inline]
 __alloc_pages_slowpath+0x10d8/0x27a0 mm/page_alloc.c:5114
 __alloc_pages+0x332/0x470 mm/page_alloc.c:5500
 alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146
 __read_swap_cache_async+0x1b5/0xa70 mm/swap_state.c:459
 read_swap_cache_async mm/swap_state.c:525 [inline]
 swap_cluster_readahead+0x6a2/0x7c0 mm/swap_state.c:661
 swapin_readahead+0xf3/0xaa0 mm/swap_state.c:854
 do_swap_page+0x4b6/0x1f40 mm/memory.c:3622
 handle_pte_fault mm/memory.c:4654 [inline]
 __handle_mm_fault mm/memory.c:4785 [inline]
 handle_mm_fault+0x1ad7/0x43b0 mm/memory.c:4883
 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1357
 handle_page_fault arch/x86/mm/fault.c:1445 [inline]
 exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1501
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f1edd6569c0
Code: Unable to access opcode bytes at RIP 0x7f1edd656996.
RSP: 002b:00007ffd8d5f59b0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000100000 RCX: 00007f1edd795380
RDX: 0000000000000000 RSI: ffffffff80086301 RDI: 0000000000000003
RBP: 00007f1edd9ed3f8 R08: 00000000000000da R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000003 R14: 00007ffd8d5f5c98 R15: 0000000000000000
 </TASK>