INFO: task syz.8.7398:27490 blocked for more than 145 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.8.7398 state:D stack:24040 pid:27490 tgid:27490 ppid:16611 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:565 [inline]
__fuse_request_send fs/fuse/dev.c:579 [inline]
__fuse_simple_request+0xf1b/0x18e0 fs/fuse/dev.c:673
fuse_simple_request fs/fuse/fuse_i.h:1244 [inline]
fuse_flush+0x5dd/0x810 fs/fuse/file.c:476
filp_flush+0xbd/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/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f696e8aeec9
RSP: 002b:00007fffc4fbec88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00000000001b754d RCX: 00007f696e8aeec9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f696eb07da0 R08: 0000000000000001 R09: 00000008c4fbef7f
R10: 0000001b32220000 R11: 0000000000000246 R12: 00007f696eb05fac
R13: 00007f696eb05fa0 R14: ffffffffffffffff R15: 00007fffc4fbeda0
Showing all locks held in the system:
1 lock held by khungtaskd/39:
#0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5563:
#0: ffff88823bf6c0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e832e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
5 locks held by kworker/u8:1/11406:
3 locks held by syz-executor/16859:
10 locks held by syz-executor/18217:
2 locks held by kworker/u8:29/20024:
#0: ffff88813ff29138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88813ff29138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90007b9fbc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90007b9fbc0 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
1 lock held by syz.1.8526/30311:
2 locks held by modprobe/30315:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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+0x436/0x7d0 arch/x86/kernel/process.c:148
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: 30311 Comm: syz.1.8526 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:preempt_count_add+0x2b/0x1a0 kernel/sched/core.c:5789
Code: 0f 1e fa 41 57 41 56 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0 60 83 89 98 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 f1 00 00 00 <83> 3d be fc fa 16 00 75 07 65 8b 05 85 c9 ef 0f 65 01 3d 7e c9 ef
RSP: 0018:ffffc90004fb7638 EFLAGS: 00000297
RAX: 0000000000000004 RBX: ffff88803ca02240 RCX: ffffffff98898303
RDX: 0000000000000000 RSI: ffffffff8cd67016 RDI: 0000000000000001
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8ab327a1
R10: 0000000000000000 R11: ffffed100d80926d R12: 1ffff110042e6090
R13: ffff888021730000 R14: ffff888021730480 R15: dffffc0000000000
FS: 00007f4f2c99d6c0(0000) GS:ffff88812713b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa58cfe56c0 CR3: 0000000032ad8000 CR4: 00000000003526f0
Call Trace:
class_preempt_constructor include/linux/preempt.h:470 [inline]
__migrate_enable include/linux/sched.h:2366 [inline]
migrate_enable include/linux/sched.h:2417 [inline]
rt_spin_unlock+0x6e/0x200 kernel/locking/spinlock_rt.c:81
spin_unlock_irqrestore include/linux/spinlock_rt.h:122 [inline]
__skb_try_recv_datagram+0xa9/0x1b0 net/core/datagram.c:267
__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/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4f2e75eec9
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:00007f4f2c99d038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f4f2e9b6090 RCX: 00007f4f2e75eec9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f4f2e7e1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4f2e9b6128 R14: 00007f4f2e9b6090 R15: 00007ffee8534dd8