INFO: task udevd:25962 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:23176 pid:25962 tgid:25962 ppid:4999   task_flags:0x400040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5388 [inline]
 __schedule+0x1821/0x5740 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
 wait_for_reconnect drivers/block/nbd.c:1107 [inline]
 nbd_handle_cmd drivers/block/nbd.c:1149 [inline]
 nbd_queue_rq+0x857/0x1100 drivers/block/nbd.c:1207
 blk_mq_dispatch_rq_list+0xa70/0x1910 block/blk-mq.c:2148
 __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
 blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
 __blk_mq_sched_dispatch_requests+0xdcc/0x1600 block/blk-mq-sched.c:307
 blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
 blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2386
 blk_mq_dispatch_list+0xd16/0xe10 include/linux/spinlock.h:-1
 blk_mq_flush_plug_list+0x48d/0x570 block/blk-mq.c:2997
 __blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230
 blk_finish_plug block/blk-core.c:1257 [inline]
 __submit_bio+0x28d/0x580 block/blk-core.c:649
 __submit_bio_noacct_mq block/blk-core.c:722 [inline]
 submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:753
 submit_bh fs/buffer.c:2742 [inline]
 block_read_full_folio+0x7b7/0x830 fs/buffer.c:2358
 filemap_read_folio+0x137/0x3b0 mm/filemap.c:2502
 do_read_cache_folio+0x358/0x590 mm/filemap.c:4107
 read_mapping_folio include/linux/pagemap.h:1017 [inline]
 read_part_sector+0xb6/0x2b0 block/partitions/core.c:724
 adfspart_check_ICS+0xb1/0x960 block/partitions/acorn.c:356
 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+0x822/0x13a0 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+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f68192a7407
RSP: 002b:00007ffd14d39610 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f6819aa2880 RCX: 00007f68192a7407
RDX: 00000000000a0800 RSI: 0000558c34c36480 RDI: ffffffffffffff9c
RBP: 0000558c34c35910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000558c34c6ce60
R13: 0000558c34c43190 R14: 00007ffd14d396d8 R15: 0000558c34c6ce60
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u8:0/12:
 #0: ffff88801be8e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff88801be8e140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90000117c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90000117c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8fdba0e8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
 #3: ffffffff8fdc8e00 (rtnl_mutex){+.+.}-{4:4}, at: cfg802154_pernet_exit+0x19/0xe0 net/ieee802154/core.c:351
1 lock held by khungtaskd/30:
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5386:
 #0: ffff8880317590a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211
3 locks held by kworker/u8:10/7032:
3 locks held by kworker/u8:12/7038:
 #0: ffff888031414140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
 #0: ffff888031414140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
 #1: ffffc90007227c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
 #1: ffffc90007227c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
 #2: ffffffff8fdc8e00 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #2: ffffffff8fdc8e00 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4221
5 locks held by kworker/u8:13/7041:
3 locks held by udevd/25962:
 #0: ffff888026dd0350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953
 #1: ffff888025598998 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
 #1: ffff888025598998 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
 #1: ffff888025598998 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0 block/blk-mq.c:2386
 #2: ffff888026e351f8 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc6/0x1100 drivers/block/nbd.c:1199
7 locks held by syz-executor/29898:
 #0: ffff888031c30410 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline]
 #0: ffff888031c30410 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 fs/read_write.c:684
 #1: ffff88806c0af080 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343
 #2: ffff88802933c3c8 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff88802933c3c8 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344
 #3: ffffffff8f655240 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
 #4: ffff8880335ae128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #4: ffff8880335ae128 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
 #4: ffff8880335ae128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1372
 #5: ffff8880335ad258 (&devlink->lock_key#7){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1799
 #6: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
 #6: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
1 lock held by syz.3.6045/30221:
 #0: ffffffff8fdc8e00 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:641 [inline]
 #0: ffffffff8fdc8e00 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3505
1 lock held by syz.2.6046/30230:
 #0: ffffffff8fdcc700 (bpf_dispatcher_xdp.mutex){+.+.}-{4:4}, at: bpf_dispatcher_change_prog+0xc6/0xd70 kernel/bpf/dispatcher.c:146
2 locks held by syz.0.6047/30228:
 #0: ffffffff8fdba0e8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8fdc8e00 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840 net/ipv4/ip_tunnel.c:1146
6 locks held by syz.0.6047/30232:
 #0: ffffffff8fdba0e8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
 #1: ffffffff8fb1af48 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1188
 #2: ffffffff8fb1b108 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1193
 #3: ffff88807e53cfe0 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650 drivers/infiniband/core/device.c:952
 #4: ffff88807e53d2d0 (&rxe->usdev_lock){+.+.}-{4:4}, at: rxe_query_port+0x7e/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:61
 #5: ffffffff8fdc8e00 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x173/0x7f0 drivers/infiniband/core/verbs.c:2054

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 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: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+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x389/0x470 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: 30251 Comm: sed Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:validate_mm+0x0/0x4c0 mm/vma.c:646
Code: 00 e9 3c ff ff ff e8 4f 3a 88 09 66 66 66 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 <f3> 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48
RSP: 0018:ffffc90003f4f718 EFLAGS: 00000246
RAX: 1ffff1100d903452 RBX: ffff88806c81a290 RCX: ffff88802c61dd00
RDX: 0000000000000000 RSI: 0000000000000042 RDI: ffff88807d05ee40
RBP: ffffc90003f4f888 R08: ffff88807d05f867 R09: 1ffff1100fa0bf0c
R10: dffffc0000000000 R11: ffffed100fa0bf0d R12: ffffc90003f4fdc0
R13: dffffc0000000000 R14: f8f8f8f8f1f1f1f1 R15: 1ffff920007e9ef4
FS:  00007fd4c8845c80(0000) GS:ffff88812528b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd4c8bad000 CR3: 0000000060860000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __split_vma+0x916/0xa50 mm/vma.c:570
 split_vma mm/vma.c:599 [inline]
 vma_modify+0x97e/0x1e10 mm/vma.c:1699
 vma_modify_flags+0x24b/0x330 mm/vma.c:1719
 mprotect_fixup+0x62a/0xb60 mm/mprotect.c:789
 do_mprotect_pkey+0x8d5/0xd20 mm/mprotect.c:967
 __do_sys_mprotect mm/mprotect.c:988 [inline]
 __se_sys_mprotect mm/mprotect.c:985 [inline]
 __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:985
 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: 0033:0x7fd4c8bdc2c7
Code: 89 3d fd 3f 01 00 eb 90 0f 1f 00 f7 d8 89 05 f0 3f 01 00 48 c7 c0 ff ff ff ff eb 91 0f 1f 80 00 00 00 00 b8 0a 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8d 0d c9 3f 01 00 f7 d8 89 01 48 83
RSP: 002b:00007ffefee95828 EFLAGS: 00000206 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007fd4c8bf0310 RCX: 00007fd4c8bdc2c7
RDX: 0000000000000001 RSI: 0000000000001000 RDI: 00005582f729c000
RBP: 00007ffefee95af0 R08: 0000000000000000 R09: 00007fd4c8b6d908
R10: 00007fd4c8bf0310 R11: 0000000000000206 R12: 0000000000000000
R13: 000001c645a8d621 R14: 0000000000000000 R15: 00007fd4c8bf0310
 </TASK>