INFO: task syz.0.46:6102 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.46        state:D stack:27880 pid:6102  ppid:5962   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5393 [inline]
 __schedule+0x156f/0x4720 kernel/sched/core.c:6722
 schedule+0xbd/0x170 kernel/sched/core.c:6796
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6855
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x689/0xce0 kernel/locking/mutex.c:747
 blkdev_put+0x100/0x7a0 block/bdev.c:940
 blkdev_release+0x84/0x90 block/fops.c:604
 __fput+0x221/0x940 fs/file_table.c:418
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 get_signal+0x11da/0x1390 kernel/signal.c:2703
 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
 __syscall_exit_to_user_mode_work kernel/entry/common.c:294 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:305
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb4ac9a8f19
RSP: 002b:00007fb4ad861028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007fb4acc25fa0 RCX: 00007fb4ac9a8f19
RDX: 0000000000000000 RSI: 000000000000ab03 RDI: 0000000000000003
RBP: 00007fb4aca37f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb4acc26038 R14: 00007fb4acc25fa0 R15: 00007ffdb987aa98
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8e1322e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8e1322e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8e1322e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6669
2 locks held by getty/5543:
 #0: ffff88814bf4b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc900032862f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x43a/0x1400 drivers/tty/n_tty.c:2217
1 lock held by udevd/5974:
 #0: ffff888022ca14c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by udevd/5975:
 #0: ffff888022c634c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by udevd/5976:
 #0: ffff888022bbc4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by syz.0.46/6102:
 #0: ffff888022bbc4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x7a0 block/bdev.c:940
1 lock held by syz.1.81/6196:
 #0: ffff888022c634c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x7a0 block/bdev.c:940
1 lock held by syz.2.92/6231:
 #0: ffff888022ca14c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x7a0 block/bdev.c:940
1 lock held by udevd/6295:
 #0: ffff888022ca64c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by syz.3.139/6356:
 #0: ffff888022ca64c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x7a0 block/bdev.c:940
1 lock held by udevd/6367:
 #0: ffff888022d6b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x11b/0x610 block/bdev.c:801
1 lock held by syz.4.163/6433:
 #0: ffff888022d6b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x100/0x7a0 block/bdev.c:940

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf59/0xfa0 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6278 Comm: kworker/u4:4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:178 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x10/0x60 kernel/kcov.c:212
Code: 89 fb e8 13 00 00 00 48 8b 3d 0c fe 05 0e 48 89 de 5b e9 23 37 58 00 cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 50 d9 7b 7e <65> 8b 15 51 d9 7b 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75
RSP: 0018:ffffc900020af5b0 EFLAGS: 00000246
RAX: ffffffff813be8b2 RBX: ffffffff8f9d00e8 RCX: ffff88802db9da00
RDX: 0000000000000000 RSI: ffffffff8131ada7 RDI: ffffffff8131ad98
RBP: ffffffff8f9d00e4 R08: ffffc900020af750 R09: 0000000000000009
R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff8131ad98
R13: ffffffff8f9d00e8 R14: ffffffff8131ada7 R15: ffffffff8f9d00e4
FS:  0000000000000000(0000) GS:ffff8880b8c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558eda54e8 CR3: 000000000df32000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 __orc_find arch/x86/kernel/unwind_orc.c:99 [inline]
 orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
 unwind_next_frame+0x4e2/0x2990 arch/x86/kernel/unwind_orc.c:494
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 ____kasan_kmalloc mm/kasan/common.c:375 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1007 [inline]
 __kmalloc_node_track_caller+0xb4/0x230 mm/slab_common.c:1027
 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
 alloc_skb include/linux/skbuff.h:1316 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x253/0xa90 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>