INFO: task syz.5.8256:25720 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.8256 state:D
stack:27008 pid:25720 tgid:25719 ppid:18186 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0x153e/0x4fe0 kernel/sched/core.c:6907
__schedule_loop kernel/sched/core.c:6989 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7004
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
nfsd_nl_version_get_doit+0x17c/0xc40 fs/nfsd/nfsctl.c:1811
genl_family_rcv_msg_doit+0x22a/0x330 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x61c/0x7a0 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x80f/0x9b0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737
__sock_sendmsg net/socket.c:752 [inline]
____sys_sendmsg+0x589/0x8c0 net/socket.c:2610
___sys_sendmsg+0x2a5/0x360 net/socket.c:2664
__sys_sendmsg net/socket.c:2696 [inline]
__do_sys_sendmsg net/socket.c:2701 [inline]
__se_sys_sendmsg net/socket.c:2699 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2699
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f92df99acb9
RSP: 002b:00007f92e0839028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f92dfc15fa0 RCX: 00007f92df99acb9
RDX: 0000000020048000 RSI: 0000200000000140 RDI: 0000000000000003
RBP: 00007f92dfa08bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f92dfc16038 R14: 00007f92dfc15fa0 R15: 00007ffdd3d71b88
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e55dda0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e55dda0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e55dda0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by udevd/5199:
#0: ffff88801c28d988 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0x9e/0x5e0 fs/kernfs/dir.c:1185
2 locks held by getty/5581:
#0: ffff8880323480a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:4/5929:
#0: ffff888021eea148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x855/0x15a0 kernel/workqueue.c:3254
#1: ffffc900045ffc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x87c/0x15a0 kernel/workqueue.c:3255
#2: ffff888029ba9198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#2: ffff888029ba9198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899
2 locks held by syz.0.7228/23469:
#0: ffffffff8fa24970 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e87f6e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x141/0x16c0 fs/nfsd/nfsctl.c:1886
2 locks held by syz.5.8256/25720:
#0: ffffffff8fa24970 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e87f6e8 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x17c/0xc40 fs/nfsd/nfsctl.c:1811
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xf90/0xfe0 kernel/hung_task.c:515
kthread+0x388/0x470 kernel/kthread.c:467
ret_from_fork+0x51b/0xa40 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: 5815 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/13/2026
RIP: 0010:x86_task_fpu arch/x86/kernel/fpu/core.c:63 [inline]
RIP: 0010:fpregs_restore_userregs+0x21/0x1e0 arch/x86/kernel/fpu/context.h:56
Code: 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 49 bc 00 00 00 00 00 fc ff df e8 37 19 58 00 65 48 8b 1d a7 45 88 11 <4c> 8d 7b 2c 4d 89 fd 49 c1 ed 03 43 0f b6 44 25 00 84 c0 0f 85 23
RSP: 0018:ffffc90003fcfea0 EFLAGS: 00000093
RAX: ffffffff816aba59 RBX: ffff888011d3dac0 RCX: ffff888011d3dac0
RDX: 0000000000000000 RSI: 0000000000080000 RDI: 0000000000080000
RBP: ffffc90003fcff38 R08: ffff888011d3dac7 R09: 1ffff110023a7b58
R10: dffffc0000000000 R11: ffffed10023a7b59 R12: dffffc0000000000
R13: 00000000000000e6 R14: ffffc90003fcff48 R15: ffff888011d3dac0
FS: 0000555567de0500(0000) GS:ffff8881257f0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efd89de1198 CR3: 0000000031aa6000 CR4: 00000000003526f0
Call Trace:
arch_exit_to_user_mode_prepare+0x9d/0xc0 arch/x86/include/asm/entry-common.h:66
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:228 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x163/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f429bf55ed7
Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc2d8cb830 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 0000555567de0500 RCX: 00007f429bf55ed7
RDX: 00007ffc2d8cb870 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffc2d8cbd50 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004
R13: 00007ffc2d8cb8ac R14: 00007ffc2d8cb940 R15: 0000000000000000