INFO: task udevd:5848 blocked for more than 143 seconds.
      Not tainted syzkaller #0
      Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:23176 pid:5848  tgid:5848  ppid:5200   task_flags:0x40054c flags:0x00080803
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5260 [inline]
 __schedule+0x14ea/0x5050 kernel/sched/core.c:6867
 __schedule_loop kernel/sched/core.c:6949 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:6964
 io_schedule+0x7f/0xd0 kernel/sched/core.c:7791
 folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323
 __folio_lock mm/filemap.c:1699 [inline]
 folio_lock include/linux/pagemap.h:1170 [inline]
 __filemap_get_folio_mpol+0x13e/0xb00 mm/filemap.c:1954
 __filemap_get_folio include/linux/pagemap.h:774 [inline]
 truncate_inode_pages_range+0x48b/0xe30 mm/truncate.c:413
 kill_bdev block/bdev.c:91 [inline]
 blkdev_flush_mapping+0x109/0x2f0 block/bdev.c:729
 blkdev_put_whole block/bdev.c:736 [inline]
 bdev_release+0x417/0x650 block/bdev.c:1161
 blkdev_release+0x15/0x20 block/fops.c:706
 __fput+0x44f/0xa70 fs/file_table.c:468
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x69b/0x2310 kernel/exit.c:971
 do_group_exit+0x21b/0x2d0 kernel/exit.c:1112
 get_signal+0x1284/0x1330 kernel/signal.c:3034
 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
 exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3b91ea7407
RSP: 002b:00007ffdb667a040 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: fffffffffffffffc RBX: 00007f3b9253e880 RCX: 00007f3b91ea7407
RDX: 0000000000000200 RSI: 00007f3b9253d000 RDI: 0000000000000009
RBP: 0000555ad44ef050 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 0000000000000000 R14: 0000555ad44fbdb8 R15: 00007f3b9260339c
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8e55a360 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:9/3076:
 #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
 #0: ffff88813fe69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9d4/0x17a0 kernel/workqueue.c:3340
 #1: ffffc9000bab7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
 #1: ffffc9000bab7bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa0f/0x17a0 kernel/workqueue.c:3340
 #2: ffffffff8f9aab48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by getty/5588:
 #0: ffff888034d550a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
1 lock held by udevd/5848:
 #0: ffff888025433358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1145
1 lock held by syz.3.4647/26615:
 #0: ffffffff8f9aab48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f9aab48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newroute+0x12b/0x250 net/ipv4/fib_frontend.c:922
1 lock held by syz.3.4647/26620:
 #0: ffffffff8f9aab48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8f9aab48 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x722/0xbe0 net/core/rtnetlink.c:6964
3 locks held by syz.2.4649/26618:
 #0: ffffffff8ff12148 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8ff12148 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8ff12148 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f9aab48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f9aab48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f9aab48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
 #2: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #2: ffffffff8e560c78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:956
2 locks held by dhcpcd-run-hook/26635:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline]
 watchdog+0xf90/0xfe0 kernel/hung_task.c:515
 kthread+0x726/0x8b0 kernel/kthread.c:463
 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 26615 Comm: syz.3.4647 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:__read_once_word_nocheck+0x0/0x10 include/asm-generic/rwonce.h:67
Code: 46 01 b7 00 48 ba 00 00 00 00 00 fc ff df e9 88 fc ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <48> 8b 07 e9 58 02 24 0a cc cc cc cc cc cc cc cc 90 90 90 90 90 90
RSP: 0018:ffffc90000007818 EFLAGS: 00000202
RAX: ffffc90000007a01 RBX: ffffc90000000000 RCX: 0000000000000001
RDX: ffffc900000079e8 RSI: dffffc0000000000 RDI: ffffc90000007a30
RBP: 1ffff92000000f35 R08: ffffc90000007a30 R09: 0000000000000000
R10: ffffc900000079f8 R11: fffff52000000f41 R12: 1ffff92000000f36
R13: 1ffff92000000f37 R14: ffffc90000008000 R15: dffffc0000000000
FS:  00007fa4652336c0(0000) GS:ffff8881256f8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7a3cb0e368 CR3: 000000007a29e000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 deref_stack_reg+0x19f/0x230 arch/x86/kernel/unwind_orc.c:422
 unwind_next_frame+0x18c6/0x23c0 arch/x86/kernel/unwind_orc.c:-1
 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6674 [inline]
 kmem_cache_free+0x195/0x610 mm/slub.c:6785
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core+0xc9e/0x1750 kernel/rcu/tree.c:2857
 handle_softirqs+0x22a/0x7c0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:console_flush_one_record arch/x86/include/asm/irqflags.h:-1 [inline]
RIP: 0010:console_flush_all+0x801/0xb20 kernel/printk/printk.c:3289
Code: ff ff e8 42 07 21 00 90 0f 0b 90 e9 85 fc ff ff e8 34 07 21 00 e8 4f 6f f3 09 48 85 db 74 c0 e8 25 07 21 00 fb 48 8b 5c 24 08 <48> 8b 44 24 20 42 80 3c 20 00 4c 8b 74 24 18 74 08 4c 89 f7 e8 c6
RSP: 0018:ffffc90003d6e840 EFLAGS: 00000293
RAX: ffffffff81a36fdb RBX: ffffc90003d6e9a0 RCX: ffff8880255d0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003d6e950 R08: ffffffff8fef0577 R09: 1ffffffff1fde0ae
R10: dffffc0000000000 R11: fffffbfff1fde0af R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff8edee8e0
 __console_flush_and_unlock kernel/printk/printk.c:3319 [inline]
 console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3359
 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2426
 _printk+0xdd/0x130 kernel/printk/printk.c:2451
 validate_nla lib/nlattr.c:414 [inline]
 __nla_validate_parse+0x1774/0x2dc0 lib/nlattr.c:635
 __nla_parse+0x40/0x60 lib/nlattr.c:732
 nla_parse_nested_deprecated include/net/netlink.h:1379 [inline]
 ip6_tun_build_state+0x10e/0x710 net/ipv4/ip_tunnel_core.c:965
 lwtunnel_build_state+0x384/0x4c0 net/core/lwtunnel.c:137
 fib_nh_common_init+0x131/0x3d0 net/ipv4/fib_semantics.c:628
 fib_nh_init+0x9e/0x410 net/ipv4/fib_semantics.c:654
 fib_create_info+0x1bd6/0x31f0 net/ipv4/fib_semantics.c:1442
 fib_table_insert+0xc8/0x1b50 net/ipv4/fib_trie.c:1212
 inet_rtm_newroute+0x14f/0x250 net/ipv4/fib_frontend.c:930
 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6958
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa68/0xad0 net/socket.c:2592
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2646
 __sys_sendmsg net/socket.c:2678 [inline]
 __do_sys_sendmsg net/socket.c:2683 [inline]
 __se_sys_sendmsg net/socket.c:2681 [inline]
 __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2681
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa46439aeb9
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:00007fa465233028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fa464615fa0 RCX: 00007fa46439aeb9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000003
RBP: 00007fa464408c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa464616038 R14: 00007fa464615fa0 R15: 00007fff989d5368
 </TASK>