INFO: task syz.0.16:6588 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc7-syzkaller-00127-g302f88ff3584 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.16        state:D stack:27464 pid:6588  tgid:6586  ppid:6447   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16fd/0x4cb0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6879
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6936
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x63a/0xe50 kernel/locking/mutex.c:747
 bdev_release+0x1a9/0x650 block/bdev.c:1128
 blkdev_release+0x15/0x20 block/fops.c:684
 __fput+0x44c/0xa70 fs/file_table.c:465
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 get_signal+0x11c5/0x1310 kernel/signal.c:2807
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x217/0x300 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f240e58e9a9
RSP: 002b:00007f240f402038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f240e7b5fa0 RCX: 00007f240e58e9a9
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007f240e610d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f240e7b5fa0 R15: 00007fff6c479788
 </TASK>
INFO: task syz.0.16:6588 is blocked on a mutex likely owned by task udevd:6504.
task:udevd           state:D stack:22024 pid:6504  tgid:6504  ppid:5172   task_flags:0x400140 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16fd/0x4cb0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6879
 io_schedule+0x81/0xe0 kernel/sched/core.c:7724
 folio_wait_bit_common+0x7ae/0xb80 mm/filemap.c:1317
 folio_wait_bit_killable mm/filemap.c:1462 [inline]
 folio_wait_locked_killable include/linux/pagemap.h:1196 [inline]
 filemap_read_folio+0x203/0x370 mm/filemap.c:2418
 do_read_cache_folio+0x350/0x590 mm/filemap.c:3894
 read_mapping_folio include/linux/pagemap.h:972 [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+0x75d/0x14b0 block/partitions/core.c:693
 blkdev_get_whole+0x380/0x510 block/bdev.c:748
 bdev_open+0x318/0xe80 block/bdev.c:957
 blkdev_open+0x3a8/0x510 block/fops.c:676
 do_dentry_open+0xde8/0x1940 fs/open.c:964
 vfs_open+0x3b/0x340 fs/open.c:1094
 do_open fs/namei.c:3896 [inline]
 path_openat+0x2ee1/0x3830 fs/namei.c:4055
 do_filp_open+0x1fa/0x410 fs/namei.c:4082
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1463
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x8a/0x300 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f59036a7407
RSP: 002b:00007ffd26bdb030 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5903d93880 RCX: 00007f59036a7407
RDX: 00000000000a0800 RSI: 00005569b302d880 RDI: ffffffffffffff9c
RBP: 00005569b3021910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00005569b3036850
R13: 00005569b3039430 R14: 0000000000000000 R15: 00005569b3036850
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8db3d160 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8db3d160 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8db3d160 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
2 locks held by getty/5564:
 #0: ffff8880301550a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by udevd/6296:
 #0: ffff888024ae3358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xda/0xe80 block/bdev.c:945
1 lock held by udevd/6504:
 #0: ffff8881433fe358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xda/0xe80 block/bdev.c:945
1 lock held by syz.0.16/6588:
 #0: ffff8881433fe358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1128
3 locks held by syz.1.420/7716:
 #0: ffff888024adf230 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x131/0xeb0 drivers/block/nbd.c:1635
 #1: ffff8880249a6278 (&q->q_usage_counter(io)#50){++++}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
 #1: ffff8880249a6278 (&q->q_usage_counter(io)#50){++++}-{0:0}, at: nbd_add_socket+0x1f1/0x9a0 drivers/block/nbd.c:1251
 #2: ffff8880249a62b0 (&q->q_usage_counter(queue)#2){+.+.}-{0:0}, at: blk_mq_freeze_queue include/linux/blk-mq.h:934 [inline]
 #2: ffff8880249a62b0 (&q->q_usage_counter(queue)#2){+.+.}-{0:0}, at: nbd_add_socket+0x1f1/0x9a0 drivers/block/nbd.c:1251
1 lock held by syz.1.420/7717:
 #0: ffff888024adf230 (&nbd->config_lock){+.+.}-{4:4}, at: nbd_ioctl+0x131/0xeb0 drivers/block/nbd.c:1635

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-00127-g302f88ff3584 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0x13f0/0x1430 kernel/hung_task.c:470
 kthread+0x711/0x890 kernel/kthread.c:464
 ret_from_fork+0x3f5/0x760 arch/x86/kernel/process.c:148
 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: 0 Comm: swapper/1 Not tainted 6.16.0-rc7-syzkaller-00127-g302f88ff3584 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 53 de 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 38 10 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 1de6edfd01e55f00 RBX: ffffffff81966588 RCX: 1de6edfd01e55f00
RDX: 0000000000000001 RSI: ffffffff8d2b5349 RDI: ffffffff8b7d6da0
RBP: ffffc90000197f20 R08: ffff8880b8932f9b R09: 1ffff110171265f3
R10: dffffc0000000000 R11: ffffed10171265f4 R12: ffffffff8f3675f0
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003953b40
FS:  0000000000000000(0000) GS:ffff888126724000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555589d09808 CR3: 000000004e276000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:749
 default_idle_call+0x72/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:325
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>