INFO: task syz.4.5999:27983 blocked for more than 143 seconds.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.5999 state:D stack:25848 pid:27983 tgid:27982 ppid:27302 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x1709/0x5530 kernel/sched/core.c:7231
__schedule_loop kernel/sched/core.c:7308 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7604
rt_mutex_slowlock_block+0x55c/0x680 kernel/locking/rtmutex.c:1670
__rt_mutex_slowlock kernel/locking/rtmutex.c:1747 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1787 [inline]
rt_mutex_slowlock+0x2d4/0x780 kernel/locking/rtmutex.c:1827
__rt_mutex_lock kernel/locking/rtmutex.c:1842 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:560 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:578
nfsd_nl_cache_flush_doit+0xe2/0x1b0 fs/nfsd/nfsctl.c:2317
genl_family_rcv_msg_doit+0x233/0x340 net/netlink/genetlink.c:1114
genl_family_rcv_msg net/netlink/genetlink.c:1194 [inline]
genl_rcv_msg+0x614/0x7a0 net/netlink/genetlink.c:1209
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1218
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7f5/0x990 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec+0x13a/0x180 net/socket.c:810
__sock_sendmsg net/socket.c:825 [inline]
____sys_sendmsg+0x565/0x870 net/socket.c:2727
___sys_sendmsg+0x2a5/0x360 net/socket.c:2781
__sys_sendmsg net/socket.c:2813 [inline]
__do_sys_sendmsg net/socket.c:2818 [inline]
__se_sys_sendmsg net/socket.c:2816 [inline]
__x64_sys_sendmsg+0x1b7/0x290 net/socket.c:2816
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4bc092de99
RSP: 002b:00007f4bbeb86028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f4bc0bb5fa0 RCX: 00007f4bc092de99
RDX: 0000000004000080 RSI: 0000200000000100 RDI: 0000000000000003
RBP: 00007f4bc09c3eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4bc0bb6038 R14: 00007f4bc0bb5fa0 R15: 00007ffd2a53c208
Showing all locks held in the system:
locks held by khungtaskd/39: 1, last CPU#1:
#0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6835
locks held by getty/5349: 2, on CPU#1:
#0: ffff888036aa30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900044cb2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211
locks held by kworker/u8:45/22077: 3, last CPU#1:
#0: ffff888033224938 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff888033224938 ((wq_completion)bat_events){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff888033224938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#1: ffffc90006a17c60 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc90006a17c60 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffc90006a17c60 ((work_completion)(&(&forw_packet_aggr->delayed_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#2: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
locks held by kworker/0:11/22340: 3, last CPU#0:
#0: ffff888035291538 ((wq_completion)wg-kex-wg2#31){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffff888035291538 ((wq_completion)wg-kex-wg2#31){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#0: ffff888035291538 ((wq_completion)wg-kex-wg2#31){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#1: ffffc90005d0fc60 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#1: ffffc90005d0fc60 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline]
#1: ffffc90005d0fc60 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ((typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))))((unsigned long)((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))) + (((__per_cpu_offset[(cpu)]))))); })->work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344
#2: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
locks held by syz.7.5805/27135: 3, on CPU#1:
#0: ffff888031e29d28 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259
#1: ffff88801daec510 (sb_writers#21){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2731 [inline]
#1: ffff88801daec510 (sb_writers#21){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683
#2: ffffffff8e6eeb78 (nfsd_mutex){+.+.}-{4:4}, at: write_ports+0xb5/0xd20 fs/nfsd/nfsctl.c:865
locks held by syz.4.5999/27983: 2, on CPU#0:
#0: ffffffff8f835c20 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217
#1: ffffffff8e6eeb78 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_cache_flush_doit+0xe2/0x1b0 fs/nfsd/nfsctl.c:2317
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122
nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65
trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 22340 Comm: kworker/0:11 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)}
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026
Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker
RIP: 0010:__bfs kernel/locking/lockdep.c:1799 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1876 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2812 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3185 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3300 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3924 [inline]
RIP: 0010:__lock_acquire+0x18b3/0x2e40 kernel/locking/lockdep.c:5254
Code: 00 00 49 8b 47 10 48 85 c0 0f 84 8b 0d 00 00 8b 0d 5a 80 28 14 39 48 5c 0f 84 6f ff ff ff 89 48 5c 49 8b 47 30 48 85 c0 74 23 <41> 0f b6 4f 2a 89 ca 80 e2 fa 80 78 2b 00 0f b6 c2 0f 44 c1 84 c0
RSP: 0018:ffffc90005d0e840 EFLAGS: 00000082
RAX: ffffc90005d0e8d0 RBX: 00000000000003cd RCX: 000000000019b7f5
RDX: ffffffff9650a3e8 RSI: ffff88802f430d80 RDI: ffff88802f430000
RBP: f4bc0c43179be39b R08: 00000000000003cd R09: 0000000000000020
R10: 0000000000000000 R11: ffffffff81a16ef0 R12: 0000000000000036
R13: ffffffff936b0710 R14: ffff88802f430d80 R15: ffffffff96512fe8
FS: 0000000000000000(0000) GS:ffff8881259f2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055d84ac99660 CR3: 000000000e1b0000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x115/0x350 kernel/locking/lockdep.c:5906
seqcount_lockdep_reader_access+0x55/0x100 include/linux/seqlock.h:73
ktime_get+0x45/0x220 kernel/time/timekeeping.c:998
clockevents_program_event+0x290/0x630 kernel/time/clockevents.c:363
hrtimer_start_range_ns+0x1ab/0x3f0 kernel/time/hrtimer.c:1530
enqueue_task+0x75/0x410 kernel/sched/core.c:2184
activate_task kernel/sched/core.c:2224 [inline]
ttwu_do_activate+0x1c8/0x640 kernel/sched/core.c:3824
ttwu_queue kernel/sched/core.c:4077 [inline]
try_to_wake_up+0x7b1/0x1430 kernel/sched/core.c:4415
__queue_work+0xc13/0x1120 kernel/workqueue.c:2446
queue_work_on+0x106/0x1d0 kernel/workqueue.c:2489
wg_packet_receive+0x11bd/0x23c0 drivers/net/wireguard/receive.c:570
wg_receive+0x75/0xa0 drivers/net/wireguard/socket.c:325
udpv6_queue_rcv_one_skb+0xe72/0xf90 net/ipv6/udp.c:842
udp6_unicast_rcv_skb+0x1ec/0x330 net/ipv6/udp.c:1027
ip6_protocol_deliver_rcu+0xd6e/0x1680 net/ipv6/ip6_input.c:479
ip6_input_finish+0x191/0x370 net/ipv6/ip6_input.c:534
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:545
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
__netif_receive_skb_one_core net/core/dev.c:6216 [inline]
__netif_receive_skb net/core/dev.c:6329 [inline]
process_backlog+0x3bf/0xc50 net/core/dev.c:6680
__napi_poll+0xae/0x550 net/core/dev.c:7739
napi_poll net/core/dev.c:7802 [inline]
net_rx_action+0x621/0xd70 net/core/dev.c:7959
handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:626
__do_softirq kernel/softirq.c:660 [inline]
__local_bh_enable_ip+0x170/0x2b0 kernel/softirq.c:302
local_bh_enable include/linux/bottom_half.h:33 [inline]
read_unlock_bh include/linux/rwlock_rt.h:73 [inline]
wg_socket_send_skb_to_peer+0x199/0x200 drivers/net/wireguard/socket.c:183
wg_packet_send_handshake_response+0x1ac/0x2d0 drivers/net/wireguard/send.c:103
wg_receive_handshake_packet drivers/net/wireguard/receive.c:154 [inline]
wg_packet_handshake_receive_worker+0x72a/0x10a0 drivers/net/wireguard/receive.c:213
process_one_work+0xaaf/0x1480 kernel/workqueue.c:3379
process_scheduled_works kernel/workqueue.c:3462 [inline]
worker_thread+0xb05/0x10d0 kernel/workqueue.c:3543
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245