INFO: task syz.5.10542:29496 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.10542 state:D stack:25128 pid:29496 tgid:29496 ppid:27406 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:1547
filp_close+0x1d/0x40 fs/open.c:1560
__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: 0033:0x7f5b16eaeec9
RSP: 002b:00007fff15f54ea8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007f5b17107da0 RCX: 00007f5b16eaeec9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f5b17107da0 R08: 00000000000000a4 R09: 0000000915f5519f
R10: 00000000003ffd38 R11: 0000000000000246 R12: 00000000000f7372
R13: 00007f5b17106180 R14: ffffffffffffffff R15: 00007fff15f54fc0
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d3a9a40 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d3a9a40 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d3a9a40 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5566:
#0: ffff88823bf248a0 (&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
2 locks held by syz-executor/5798:
6 locks held by kworker/u8:15/6404:
#0: ffff88801a2ec138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88801a2ec138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90005e97bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90005e97bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8e64e640 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x820 net/core/net_namespace.c:669
#3: ffff88805cd940d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff88805cd940d8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
#3: ffff88805cd940d8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0 net/devlink/core.c:506
#4: ffff88805cd91300 (&devlink->lock_key#10){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline]
#4: ffff88805cd91300 (&devlink->lock_key#10){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
#4: ffff88805cd91300 (&devlink->lock_key#10){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0 net/devlink/core.c:506
#5: ffffffff8e65b578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#5: ffffffff8e65b578 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0 net/core/dev.c:2082
3 locks held by kworker/0:1/12040:
#0: ffff888019498938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888019498938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9001e047bc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9001e047bc0 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff88805f1fe260 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x2ac/0x31b0 drivers/net/netdevsim/fib.c:1490
2 locks held by syz-executor/31881:
#0: ffffffff8ddcfa80 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8ddcfa80 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8ddcfa80 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8e65b578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8e65b578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8e65b578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
1 lock held by syz.0.11640/32128:
#0: ffff88805a637778 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:979 [inline]
#0: ffff88805a637778 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:648 [inline]
#0: ffff88805a637778 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1442
2 locks held by syz-executor/32133:
=============================================
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 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:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 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: 32130 Comm: syz.0.11640 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:check_preemption_disabled+0x40/0x120 lib/smp_processor_id.c:53
Code: 08 65 8b 05 b6 db c9 06 65 8b 0d ab db c9 06 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d 8b db c9 06 48 3b 4c 24 08 0f 85 cc 00 00 00 <48> 83 c4 10 5b 41 5e 41 5f 5d c3 cc cc cc cc cc 48 c7 04 24 00 00
RSP: 0018:ffffc9000679f468 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff8880293f0000 RCX: 37ab789388d47a00
RDX: 0000000000000006 RSI: ffffffff8cd6e5cf RDI: ffffffff8b1d96e0
RBP: ffffc9000679f570 R08: ffffffff8eb5bf37 R09: 1ffffffff1d6b7e6
R10: dffffc0000000000 R11: fffffbfff1d6b7e7 R12: ffff8880293f0b88
R13: ffff8880337a5940 R14: ffff8880293f0b88 R15: 0000000000000001
FS: 00007f171a8346c0(0000) GS:ffff888127122000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fef8f8cfc0e CR3: 00000000300ee000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
lockdep_hardirqs_on_prepare+0x1b4/0x2a0 kernel/locking/lockdep.c:4411
trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:78
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
_raw_spin_unlock_irqrestore+0x85/0x110 kernel/locking/spinlock.c:194
unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline]
rt_mutex_slowunlock+0x493/0x8a0 kernel/locking/rtmutex.c:1454
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+0x183/0x1c0 net/socket.c:1065
____sys_recvmsg+0x3ab/0x470 net/socket.c:2835
___sys_recvmsg+0x1b5/0x510 net/socket.c:2879
do_recvmmsg+0x30d/0x770 net/socket.c:2974
__sys_recvmmsg net/socket.c:3048 [inline]
__do_sys_recvmmsg net/socket.c:3071 [inline]
__se_sys_recvmmsg net/socket.c:3064 [inline]
__x64_sys_recvmmsg+0x190/0x240 net/socket.c:3064
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: 0033:0x7f171c60eec9
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:00007f171a834038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f171c866180 RCX: 00007f171c60eec9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f171c691f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f171c866218 R14: 00007f171c866180 R15: 00007ffd02541328