INFO: task udevd:5837 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:21832 pid:5837  tgid:5837  ppid:5194   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x17b4/0x5680 kernel/sched/core.c:7183
 __schedule_loop kernel/sched/core.c:7262 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7277
 io_schedule+0x7f/0xd0 kernel/sched/core.c:8104
 folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323
 folio_put_wait_locked mm/filemap.c:1492 [inline]
 do_read_cache_folio+0x1ad/0x590 mm/filemap.c:4088
 read_mapping_folio include/linux/pagemap.h:1017 [inline]
 read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
 adfspart_check_POWERTEC+0x9a/0x7a0 block/partitions/acorn.c:450
 check_partition block/partitions/core.c:143 [inline]
 blk_add_partitions block/partitions/core.c:591 [inline]
 bdev_disk_changed+0x817/0x1770 block/partitions/core.c:695
 blkdev_get_whole+0x380/0x510 block/bdev.c:756
 bdev_open+0x31e/0xd30 block/bdev.c:965
 blkdev_open+0x470/0x610 block/fops.c:697
 do_dentry_open+0x785/0x14e0 fs/open.c:947
 vfs_open+0x3b/0x340 fs/open.c:1079
 do_open fs/namei.c:4699 [inline]
 path_openat+0x2e08/0x3860 fs/namei.c:4858
 do_file_open+0x23e/0x4a0 fs/namei.c:4887
 do_sys_openat2+0x113/0x200 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_openat fs/open.c:1386 [inline]
 __se_sys_openat fs/open.c:1381 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1381
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe621ea7407
RSP: 002b:00007ffc1bb96310 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fe62257b880 RCX: 00007fe621ea7407
RDX: 00000000000a0800 RSI: 000055e8e1aeb280 RDI: ffffffffffffff9c
RBP: 000055e8e1aea910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055e8e1b224b0
R13: 000055e8e1af8190 R14: 0000000000000000 R15: 000055e8e1b224b0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by dhcpcd/5489:
 #0: ffff88807bf406e8 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404
 #1: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6863
2 locks held by getty/5584:
 #0: ffff8880332460a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
1 lock held by udevd/5837:
 #0: ffff8880276f3350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953
4 locks held by kworker/u8:23/14251:
 #0: ffff88801be9e940 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3263 [inline]
 #0: ffff88801be9e940 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3371
 #1: ffffc9000609fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3264 [inline]
 #1: ffffc9000609fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3371
 #2: ffffffff8fdc01c8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
 #3: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_pernet_exit+0x19/0x120 net/wireless/core.c:1810
2 locks held by syz.2.4124/20992:
 #0: ffffffff8fdc01c8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: cfg80211_pernet_exit+0x19/0x120 net/wireless/core.c:1810
3 locks held by syz.4.4142/21059:
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4108
 #1: ffff888049230dc8 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2821 [inline]
 #1: ffff888049230dc8 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
 #1: ffff888049230dc8 (&dev_instance_lock_key#24){+.+.}-{4:4}, at: do_setlink+0x3d2/0x45a0 net/core/rtnetlink.c:3090
 #2: ffffffff8e963328 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #2: ffffffff8e963328 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.1.4144/21053:
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x83c/0x1150 net/core/dev_ioctl.c:842
1 lock held by syz.3.4145/21057:
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3080
1 lock held by syz.3.4145/21064:
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30 net/ipv4/devinet.c:1120
1 lock held by syz.0.4146/21067:
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3080
1 lock held by syz.0.4146/21068:
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3438
1 lock held by syz.0.4146/21069:
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150 net/core/dev_ioctl.c:815
1 lock held by syz.0.4146/21070:
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
 #0: ffffffff8fdcee80 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3438

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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+0xfaa/0x1000 kernel/hung_task.c:515
 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17189 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__rcu_read_lock+0x31/0x60 kernel/rcu/tree_plugin.h:416
Code: 8b 1d 8b 7c 92 11 48 81 c3 c4 04 00 00 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 18 ff 03 8b 03 <3d> 00 00 00 40 7d 07 5b c3 cc cc cc cc cc 90 0f 0b 90 eb f3 89 d9
RSP: 0018:ffffc90003417b70 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffff88801af72384 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: ffffffff8e22a5d1 RDI: ffff8880353a7c00
RBP: 0000000000000000 R08: ffffffff823ac309 R09: ffffffff8e95d020
R10: dffffc0000000000 R11: ffffed1003ad5489 R12: ffff8880353a7c00
R13: ffffffff9a506460 R14: ffff8880353a7c00 R15: ffffea0001ea3e00
FS:  0000555563abb500(0000) GS:ffff888125343000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6f2ebeb4b8 CR3: 0000000076156000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rcu_read_lock include/linux/rcupdate.h:836 [inline]
 percpu_ref_put_many include/linux/percpu-refcount.h:330 [inline]
 percpu_ref_put+0x12/0x180 include/linux/percpu-refcount.h:351
 obj_cgroup_put include/linux/memcontrol.h:794 [inline]
 __memcg_slab_free_hook+0x155/0x470 mm/memcontrol.c:3284
 memcg_slab_free_hook mm/slub.c:2484 [inline]
 slab_free mm/slub.c:6162 [inline]
 kmem_cache_free+0x37b/0x630 mm/slub.c:6295
 sk_prot_free net/core/sock.c:2284 [inline]
 __sk_destruct+0x614/0x880 net/core/sock.c:2386
 inet_release+0x143/0x190 net/ipv4/af_inet.c:442
 __sock_release net/socket.c:722 [inline]
 sock_close+0xc3/0x240 net/socket.c:1514
 __fput+0x44f/0xa60 fs/file_table.c:510
 fput_close_sync+0x11f/0x240 fs/file_table.c:615
 __do_sys_close fs/open.c:1507 [inline]
 __se_sys_close fs/open.c:1492 [inline]
 __x64_sys_close+0x7e/0x110 fs/open.c:1492
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6f2e95d04e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007ffd9fd2bca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000555563abb500 RCX: 00007f6f2e95d04e
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007ffd9fd2bd4c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000000ea
R13: 00000000000927c0 R14: 00000000000704bf R15: 00007ffd9fd2bda0
 </TASK>