INFO: task syz.5.5685:20859 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.5685 state:D stack:25160 pid:20859 tgid:20859 ppid:10458 task_flags:0x400040 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
request_wait_answer fs/fuse/dev.c:585 [inline]
__fuse_request_send fs/fuse/dev.c:599 [inline]
__fuse_simple_request+0x11d2/0x1bb0 fs/fuse/dev.c:693
fuse_simple_request fs/fuse/fuse_i.h:1250 [inline]
fuse_flush+0x5dd/0x810 fs/fuse/file.c:482
filp_flush+0xc0/0x190 fs/open.c:1549
filp_close+0x1d/0x40 fs/open.c:1562
__range_close fs/file.c:767 [inline]
__do_sys_close_range fs/file.c:826 [inline]
__se_sys_close_range+0x35c/0x650 fs/file.c:790
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0c0cd8efc9
RSP: 002b:00007ffd3c4682e8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00000000001064c0 RCX: 00007f0c0cd8efc9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f0c0cfe7da0 R08: 0000000000000001 R09: 000000083c4685df
R10: 0000001b30b20000 R11: 0000000000000246 R12: 00007f0c0cfe5fac
R13: 00007f0c0cfe5fa0 R14: ffffffffffffffff R15: 00007ffd3c468400
Showing all locks held in the system:
2 locks held by kworker/0:0/9:
6 locks held by kworker/u8:1/13:
10 locks held by ktimers/1/29:
1 lock held by rcu_tasks_trace/36:
#0: ffffffff8d5ab1c0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0xaf9/0xdf0 kernel/rcu/tasks.h:614
1 lock held by khungtaskd/38:
#0: ffffffff8d5aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5aa4c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5aa4c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:12/3571:
2 locks held by getty/5558:
#0: ffff88823bf3c8a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
5 locks held by syz-executor/5806:
2 locks held by kworker/u8:5/21456:
4 locks held by syz.1.8204/26375:
5 locks held by syz.0.8205/26385:
1 lock held by syz.4.8206/26384:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
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:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 26385 Comm: syz.0.8205 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:mark_lock+0xa0/0x190 kernel/locking/lockdep.c:4774
Code: c7 c7 f9 22 f6 8c 48 c7 c6 0e 5c e6 8c e8 78 e7 e6 ff 90 0f 0b 90 90 90 31 c9 4c 89 fe 4c 89 f7 b8 01 00 00 00 85 69 60 74 10 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 81 e1 27 09 cc 49 89 fe 49 89 f7
RSP: 0018:ffffc90014917458 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000002 RCX: ffffffff92518af8
RDX: 0000000000000002 RSI: ffff88804dbd6588 RDI: ffff88804dbd5a00
RBP: 0000000000000004 R08: 0000000000000000 R09: ffffffff88a14339
R10: dffffc0000000000 R11: fffffbfff1dac52f R12: 0000000000000004
R13: 0000000000000003 R14: ffff88804dbd6588 R15: ffff88804dbd65a8
FS: 00007fb09917d6c0(0000) GS:ffff888126efc000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3301bff8 CR3: 000000007185a000 CR4: 00000000003526f0
Call Trace:
mark_usage kernel/locking/lockdep.c:4662 [inline]
__lock_acquire+0x9b6/0xd20 kernel/locking/lockdep.c:5191
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
rt_spin_lock+0x88/0x3e0 kernel/locking/spinlock_rt.c:56
spin_lock include/linux/spinlock_rt.h:44 [inline]
__skb_try_recv_datagram+0x89/0x1b0 net/core/datagram.c:264
__unix_dgram_recvmsg+0x2d4/0xd60 net/unix/af_unix.c:2601
sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1078
____sys_recvmsg+0x3ab/0x470 net/socket.c:2848
___sys_recvmsg+0x1b5/0x510 net/socket.c:2892
do_recvmmsg+0x30d/0x770 net/socket.c:2987
__sys_recvmmsg net/socket.c:3061 [inline]
__do_sys_recvmmsg net/socket.c:3084 [inline]
__se_sys_recvmmsg net/socket.c:3077 [inline]
__x64_sys_recvmmsg+0x190/0x240 net/socket.c:3077
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb09af3efc9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb09917d038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007fb09b196090 RCX: 00007fb09af3efc9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007fb09afc1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb09b196128 R14: 00007fb09b196090 R15: 00007ffe23e1bb68
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun
vkms_vblank_simulate: vblank timer overrun