INFO: task syz.3.3404:19575 blocked for more than 143 seconds.
Tainted: G L syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.3404 state:D stack:25688 pid:19575 tgid:19575 ppid:18228 task_flags:0x400040 flags:0x00080002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x149b/0x4fd0 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
down_write_failed drivers/tty/tty_ldsem.c:262 [inline]
__ldsem_down_write_nested+0x304/0x730 drivers/tty/tty_ldsem.c:324
__tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline]
tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:352 [inline]
tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline]
tty_ldisc_release+0x110/0x200 drivers/tty/tty_ldisc.c:780
tty_release_struct+0x2a/0xd0 drivers/tty/tty_io.c:1681
tty_release+0xcb0/0x1720 drivers/tty/tty_io.c:1852
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1d4/0x260 kernel/task_work.c:233
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
__exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
exit_to_user_mode_loop+0xef/0x4e0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [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+0x2c1/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8dedf8f749
RSP: 002b:00007f8dee30fb88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f8dee1e7da0 RCX: 00007f8dedf8f749
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f8dee1e7da0 R08: 00000000000000e0 R09: 0000000cee30fe7f
R10: 00000000003ffcf8 R11: 0000000000000246 R12: 00000000000f9a2b
R13: 00007f8dee1e6090 R14: ffffffffffffffff R15: 00007f8dee30fca0
</TASK>
Showing all locks held in the system:
1 lock held by kthreadd/2:
2 locks held by kworker/0:1/10:
4 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/31:
#0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:2/36:
3 locks held by kworker/u8:3/50:
4 locks held by kworker/u8:4/60:
4 locks held by kworker/u8:5/70:
3 locks held by kworker/1:2/130:
4 locks held by kworker/u8:10/3489:
4 locks held by kworker/u8:11/3504:
3 locks held by kworker/u8:12/3573:
#0: ffff88814ca09148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814ca09148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000cdb7bc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000cdb7bc0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f311e48 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4734
3 locks held by kworker/u8:13/3866:
8 locks held by kworker/u8:14/3878:
2 locks held by klogd/5189:
3 locks held by udevd/5200:
1 lock held by dhcpcd/5494:
1 lock held by crond/5569:
2 locks held by getty/5586:
#0: ffff88803549d0a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211
3 locks held by kworker/1:4/5883:
2 locks held by kworker/0:3/5890:
2 locks held by kworker/0:6/5915:
3 locks held by kworker/1:7/5934:
2 locks held by kworker/1:8/5945:
3 locks held by kworker/1:10/5981:
4 locks held by kworker/u8:15/5982:
3 locks held by kworker/u8:17/6029:
2 locks held by kworker/u8:19/6400:
3 locks held by kworker/u8:20/6927:
4 locks held by kworker/u8:21/7257:
4 locks held by kworker/u8:22/7799:
4 locks held by kworker/1:0/17265:
2 locks held by syz-executor/17292:
4 locks held by kworker/1:3/17557:
1 lock held by syz-executor/17994:
#0: ffff888030190308 (&xt[i].mutex){+.+.}-{4:4}, at: xt_find_table_lock+0x54/0x3e0 net/netfilter/x_tables.c:1243
3 locks held by kworker/u8:6/18409:
4 locks held by kworker/u8:7/18504:
2 locks held by kworker/u8:8/18868:
1 lock held by syz.5.3399/19564:
1 lock held by syz.4.3405/19579:
1 lock held by syz.3.3404/19575:
#0: ffff8880349070a0 (&tty->ldisc_sem){++++}-{0:0}, at: __tty_ldisc_lock drivers/tty/tty_ldisc.c:289 [inline]
#0: ffff8880349070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair_timeout drivers/tty/tty_ldisc.c:352 [inline]
#0: ffff8880349070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_lock_pair drivers/tty/tty_ldisc.c:366 [inline]
#0: ffff8880349070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_release+0x110/0x200 drivers/tty/tty_ldisc.c:780
3 locks held by kworker/1:5/19584:
2 locks held by kworker/u8:9/19586:
2 locks held by kworker/1:6/19587:
3 locks held by kworker/0:9/19589:
4 locks held by kworker/u8:16/19590:
4 locks held by syz-executor/19591:
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
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:160 [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+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 18504 Comm: kworker/u8:7 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker
RIP: 0010:is_pppoe_ip net/bridge/br_netfilter_hooks.c:124 [inline]
RIP: 0010:br_nf_forward+0x2a8/0x18d0 net/bridge/br_netfilter_hooks.c:769
Code: 89 f7 e8 3b a9 ee f7 49 8b 3e 8b 35 4a 9b 4b 05 e8 fd c9 ff ff 49 89 c7 48 8b 44 24 18 42 0f b6 04 20 84 c0 0f 85 13 10 00 00 <44> 0f b7 33 bf 88 64 00 00 44 89 f6 e8 27 8a 88 f7 41 81 fe 88 64
RSP: 0018:ffffc90000a08078 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888096d38974 RCX: 0000000000000101
RDX: 0000000000000006 RSI: ffffffff8d976a7d RDI: ffff888025285b80
RBP: ffff88805887b080 R08: ffffffff8a383bae R09: ffffffff8df41aa0
R10: 0000000000000003 R11: ffffffff8a386f00 R12: dffffc0000000000
R13: ffff888096d388c0 R14: ffffc90000a081e0 R15: ffff88805887b080
FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000025a030 CR3: 000000000dd3a000 CR4: 00000000003526f0
Call Trace:
<IRQ>
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:623
nf_hook include/linux/netfilter.h:273 [inline]
NF_HOOK+0x215/0x3c0 include/linux/netfilter.h:316
__br_forward+0x397/0x540 net/bridge/br_forward.c:115
deliver_clone net/bridge/br_forward.c:131 [inline]
maybe_deliver+0xb5/0x160 net/bridge/br_forward.c:191
br_flood+0x31a/0x6a0 net/bridge/br_forward.c:238
br_handle_frame_finish+0x15a3/0x1c90 net/bridge/br_input.c:229
br_nf_hook_thresh+0x3c6/0x4a0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x999/0xd60 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x37e/0x6b0 net/bridge/br_netfilter_ipv6.c:184
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0x96e/0x14f0 net/bridge/br_input.c:442
__netif_receive_skb_core+0x95f/0x2f90 net/core/dev.c:6026
__netif_receive_skb_one_core net/core/dev.c:6137 [inline]
__netif_receive_skb+0x72/0x380 net/core/dev.c:6252
process_backlog+0x54f/0x1340 net/core/dev.c:6604
__napi_poll+0xae/0x320 net/core/dev.c:7668
napi_poll net/core/dev.c:7731 [inline]
net_rx_action+0x64a/0xe00 net/core/dev.c:7883
handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
</IRQ>
<TASK>
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
blake2s_compress+0xe0/0x1e30 lib/crypto/x86/blake2s.h:42
blake2s_final+0x116/0x270 lib/crypto/blake2s.c:142
hmac+0x293/0x330 drivers/net/wireguard/noise.c:333
kdf+0x105/0x270 drivers/net/wireguard/noise.c:367
mix_dh drivers/net/wireguard/noise.c:413 [inline]
wg_noise_handshake_create_initiation+0x278/0x750 drivers/net/wireguard/noise.c:550
wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:34 [inline]
wg_packet_handshake_send_worker+0x163/0x320 drivers/net/wireguard/send.c:51
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>