INFO: task udevd:9153 blocked for more than 143 seconds.
      Not tainted 6.16.0-syzkaller-06600-g1dbf1d590d10 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:22856 pid:9153  tgid:9153  ppid:1      task_flags:0x400140 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5351 [inline]
 __schedule+0x1737/0x4d30 kernel/sched/core.c:6954
 __schedule_loop kernel/sched/core.c:7036 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7051
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 wait_for_reconnect drivers/block/nbd.c:1104 [inline]
 nbd_handle_cmd drivers/block/nbd.c:1146 [inline]
 nbd_queue_rq+0x662/0xf10 drivers/block/nbd.c:1204
 blk_mq_dispatch_rq_list+0x4bd/0x1900 block/blk-mq.c:2120
 __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+0xda4/0x1570 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:2358
 blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
 blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
 __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
 blk_finish_plug block/blk-core.c:1247 [inline]
 __submit_bio+0x2d3/0x5a0 block/blk-core.c:649
 __submit_bio_noacct_mq block/blk-core.c:722 [inline]
 submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
 submit_bh fs/buffer.c:2829 [inline]
 block_read_full_folio+0x599/0x830 fs/buffer.c:2447
 filemap_read_folio+0x114/0x380 mm/filemap.c:2412
 do_read_cache_folio+0x350/0x590 mm/filemap.c:3923
 read_mapping_folio include/linux/pagemap.h:999 [inline]
 read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
 adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
 check_partition block/partitions/core.c:141 [inline]
 blk_add_partitions block/partitions/core.c:589 [inline]
 bdev_disk_changed+0x75c/0x14b0 block/partitions/core.c:693
 blkdev_get_whole+0x380/0x510 block/bdev.c:748
 bdev_open+0x31e/0xd30 block/bdev.c:957
 blkdev_open+0x3a8/0x510 block/fops.c:691
 do_dentry_open+0xdf3/0x1970 fs/open.c:965
 vfs_open+0x3b/0x340 fs/open.c:1095
 do_open fs/namei.c:3887 [inline]
 path_openat+0x2ee5/0x3830 fs/namei.c:4046
 do_filp_open+0x1fa/0x410 fs/namei.c:4073
 do_sys_openat2+0x121/0x1c0 fs/open.c:1435
 do_sys_open fs/open.c:1450 [inline]
 __do_sys_openat fs/open.c:1466 [inline]
 __se_sys_openat fs/open.c:1461 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1461
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa0d6ca7407
RSP: 002b:00007ffda71d46b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fa0d7401880 RCX: 00007fa0d6ca7407
RDX: 00000000000a0800 RSI: 000055661363c2a0 RDI: ffffffffffffff9c
RBP: 000055661363b910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000556613650850
R13: 0000556613653430 R14: 0000000000000000 R15: 0000556613650850
 </TASK>

Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
 #0: ffff8880b8639f58 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
1 lock held by khungtaskd/31:
 #0: ffffffff8e13c4e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13c4e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13c4e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5598:
 #0: ffff88814c5450a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/0:5/5909:
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a480d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc9000512fbc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000512fbc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffffffff8e141f38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #2: ffffffff8e141f38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998
3 locks held by udevd/9153:
 #0: ffff88802582f358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
 #1: ffff8880252cd310 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
 #1: ffff8880252cd310 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
 #1: ffff8880252cd310 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0 block/blk-mq.c:2358
 #2: ffff8880259ee178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1196
3 locks held by kworker/u8:42/9233:
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc9000e99fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000e99fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffffffff8f509008 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
3 locks held by syz-executor/15501:
 #0: ffffffff8eca3ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8eca3ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8eca3ba0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f509008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f509008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f509008 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
 #2: ffffffff8e141f38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #2: ffffffff8e141f38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-syzkaller-06600-g1dbf1d590d10 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:470
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 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: 16 Comm: rcu_preempt Not tainted 6.16.0-syzkaller-06600-g1dbf1d590d10 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 89 fb e8 23 00 00 00 48 8b 3d e4 43 fa 0b 48 89 de 5b e9 63 5c 58 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 00 9a 92 65 8b 15 68 4f
RSP: 0018:ffffc90000157988 EFLAGS: 00000046
RAX: 1ffff110170c4b29 RBX: 00000001000014fa RCX: ffff88801d2e5a00
RDX: ffffc90000157a18 RSI: 00000001000014fa RDI: 00000001000014fa
RBP: 00000000ffffffff R08: ffffffff99d225bb R09: 1ffffffff33a44b7
R10: dffffc0000000000 R11: fffffbfff33a44b8 R12: ffff8880b8625900
R13: dffffc0000000000 R14: ffffc90000157a18 R15: 00000001000014fa
FS:  0000000000000000(0000) GS:ffff888125c80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f41470dfb0 CR3: 000000000df38000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 calc_wheel_index+0x21/0x2e0 kernel/time/timer.c:543
 internal_add_timer kernel/time/timer.c:644 [inline]
 __mod_timer+0xb14/0xf30 kernel/time/timer.c:1136
 schedule_timeout+0x126/0x270 kernel/time/sleep_timeout.c:98
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 kthread+0x70e/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>