INFO: task syz.4.618:6334 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.618       state:D stack:25680 pid: 6334 ppid:  4193 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 do_uevent+0x1df/0x480 fs/dlm/lockspace.c:210
 new_lockspace fs/dlm/lockspace.c:640 [inline]
 dlm_new_lockspace+0x1ca0/0x21a0 fs/dlm/lockspace.c:698
 device_create_lockspace+0xc4/0x350 fs/dlm/user.c:405
 device_write+0x893/0xea0 fs/dlm/user.c:597
 vfs_write+0x304/0xd70 fs/read_write.c:592
 ksys_write+0x153/0x260 fs/read_write.c:647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7c89034159
RSP: 002b:00007f7c8728c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7c892bbfa0 RCX: 00007f7c89034159
RDX: 0000000000000080 RSI: 00002000000004c0 RDI: 0000000000000008
RBP: 00007f7c890cb024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7c892bc038 R14: 00007f7c892bbfa0 R15: 00007ffe7d3d2448
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31ef60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by udevd/3558:
2 locks held by getty/3943:
 #0: ffff88802ce6f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158
1 lock held by syz.4.618/6334:
 #0: ffffffff963c9aa8 (&ls_lock){+.+.}-{3:3}, at: dlm_new_lockspace+0xab/0x21a0 fs/dlm/lockspace.c:692
1 lock held by dlm_recoverd/6340:
 #0: ffff88801fd60cb8 (&ls->ls_in_recovery){+.+.}-{3:3}, at: dlm_recoverd+0xa9/0x19e0 fs/dlm/recoverd.c:286
1 lock held by syz.1.1037/8055:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe1b/0xe60 kernel/hung_task.c:369
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8055 Comm: syz.1.1037 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline]
RIP: 0010:rcu_is_watching+0x36/0xa0 kernel/rcu/tree.c:1123
Code: e8 cf d3 5b 08 89 c3 83 f8 08 73 5c 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 20 e8 e3 8b 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 e0 8c 59 00 48 c7 c3 08 b3 03 00 49 03 1e 48 89
RSP: 0018:ffffc900032efb60 EFLAGS: 00000246
RAX: 1ffffffff17c7d05 RBX: 0000000000000001 RCX: e188700cbfdda600
RDX: 0000000000000000 RSI: ffffffff8a7a4520 RDI: ffffffff8a7a44e0
RBP: ffffc900032efc90 R08: ffffffff8d8b122f R09: 1ffffffff1b16245
R10: dffffc0000000000 R11: fffffbfff1b16246 R12: 1ffff9200065df7c
R13: dffffc0000000000 R14: ffffffff8be3e828 R15: dffffc0000000000
FS:  00007f2e2e0b06c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8a796812f8 CR3: 00000000874ee000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 trace_lock_release include/trace/events/lock.h:58 [inline]
 lock_release+0xb5/0x8a0 kernel/locking/lockdep.c:5634
 do_recvmmsg+0x389/0x7f0 net/socket.c:2807
 __sys_recvmmsg net/socket.c:2880 [inline]
 __do_sys_recvmmsg net/socket.c:2903 [inline]
 __se_sys_recvmmsg net/socket.c:2896 [inline]
 __x64_sys_recvmmsg+0x195/0x250 net/socket.c:2896
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2e2fe79159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2e2e0b0028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f2e30101090 RCX: 00007f2e2fe79159
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f2e2ff10024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2e30101128 R14: 00007f2e30101090 R15: 00007ffff77a7c78
 </TASK>
vkms_vblank_simulate: vblank timer overrun