INFO: task kworker/u8:9:8868 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:9 state:D stack:21848 pid:8868 tgid:8868 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/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
INFO: task kworker/u8:22:15387 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:22 state:D stack:21192 pid:15387 tgid:15387 ppid:2 task_flags:0x4208160 flags:0x00004000
Workqueue: events_unbound linkwatch_event
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
linkwatch_event+0xe/0x60 net/core/link_watch.c:303
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/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
INFO: task syz.1.4032:21591 blocked for more than 143 seconds.
Not tainted syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.4032 state:D stack:24728 pid:21591 tgid:21586 ppid:18661 task_flags:0x40044c flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
__mutex_lock_common kernel/locking/mutex.c:676 [inline]
__mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760
tun_detach drivers/net/tun.c:634 [inline]
tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
__fput+0x44c/0xa70 fs/file_table.c:468
task_work_run+0x1d1/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:961
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbd6ed8eec9
RSP: 002b:00007fbd6fcdf038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007fbd6efe6090 RCX: 00007fbd6ed8eec9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007fbd6ee11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbd6efe6128 R14: 00007fbd6efe6090 R15: 00007fbd6f10fa28
Showing all locks held in the system:
1 lock held by kthreadd/2:
1 lock held by khungtaskd/31:
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/0:2/979:
3 locks held by kworker/u8:7/4607:
1 lock held by klogd/5223:
2 locks held by udevd/5234:
3 locks held by dhcpcd/5528:
2 locks held by crond/5607:
2 locks held by getty/5625:
#0: ffff88814cd870a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5851:
3 locks held by kworker/1:4/5943:
3 locks held by kworker/0:7/5958:
#0: ffff888056a35148 ((wq_completion)wg-kex-wg2#22){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888056a35148 ((wq_completion)wg-kex-wg2#22){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90004647bc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90004647bc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff888057ad20f0 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_begin_session+0x36/0xbd0 drivers/net/wireguard/noise.c:822
4 locks held by kworker/1:5/5964:
4 locks held by kworker/1:7/5994:
#0: ffff888033fa4d48 ((wq_completion)wg-kex-wg0#22){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888033fa4d48 ((wq_completion)wg-kex-wg0#22){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc900047a7bc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc900047a7bc0 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __ptr = (unsigned long) ((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker)))); (typeof((__typeof_unqual__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff8880315c1308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x150/0x900 drivers/net/wireguard/noise.c:598
#3: ffff888057ad2ad8 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_consume_initiation+0x4de/0x900 drivers/net/wireguard/noise.c:632
4 locks held by kworker/u8:8/8866:
3 locks held by kworker/u8:9/8868:
#0: ffff88802fabe148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88802fabe148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000f4d7bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000f4d7bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4194
3 locks held by kworker/u8:10/8869:
3 locks held by kworker/u8:13/8872:
3 locks held by kworker/0:1/11317:
3 locks held by kworker/u8:14/12314:
3 locks held by kworker/0:9/14446:
3 locks held by kworker/u8:22/15387:
#0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000441fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000441fbc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
4 locks held by kworker/u8:24/15389:
4 locks held by kworker/u8:26/15391:
#0: ffff8880242f7148 ((wq_completion)wg-kex-wg2#21){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff8880242f7148 ((wq_completion)wg-kex-wg2#21){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90003fffbc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90003fffbc0 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff8880343d9308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x10a/0x7e0 drivers/net/wireguard/noise.c:529
#3: ffff888057ad20f0 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x11b/0x7e0 drivers/net/wireguard/noise.c:530
4 locks held by kworker/0:11/15630:
7 locks held by kworker/u9:1/16134:
#0: ffff8880537d6148 ((wq_completion)hci5){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff8880537d6148 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000b4b7bc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000b4b7bc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff88806b130dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0 net/bluetooth/hci_sync.c:331
#3: ffff88806b1300b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x242/0xe30 net/bluetooth/hci_sync.c:5677
#4: ffffffff8f69f0a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2100 [inline]
#4: ffffffff8f69f0a8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x165/0x310 net/bluetooth/hci_conn.c:1313
#5: ffff88807e093b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1762
#6: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#6: ffffffff8e13fb78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957
1 lock held by syz.3.3113/18767:
#0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
2 locks held by udevd/21539:
1 lock held by syz.1.4032/21591:
#0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436
3 locks held by kworker/1:1/21603:
4 locks held by syz.9.4035/21606:
3 locks held by kworker/u8:1/21645:
2 locks held by kworker/u8:2/21654:
2 locks held by syz-executor/21656:
2 locks held by syz-executor/21657:
#0: ffffffff8f52d3b0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x304/0x4d0 net/core/net_namespace.c:566
#1: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#1: ffffffff8f53a248 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0 net/core/dev.c:2082
4 locks held by kworker/u8:3/21659:
3 locks held by syz-executor/21665:
4 locks held by kworker/1:6/21667:
=============================================
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 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+0x70e/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: 5964 Comm: kworker/1:5 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker
RIP: 0010:prefetchw arch/x86/include/asm/processor.h:638 [inline]
RIP: 0010:prefetch_freepointer mm/slub.c:529 [inline]
RIP: 0010:__slab_alloc_node mm/slub.c:4089 [inline]
RIP: 0010:slab_alloc_node mm/slub.c:4228 [inline]
RIP: 0010:kmem_cache_alloc_noprof+0x163/0x3c0 mm/slub.c:4247
Code: 48 83 f9 ff 0f 84 e7 01 00 00 48 c1 e9 3a 48 0f a3 48 08 0f 82 63 ff ff ff e8 59 b5 07 00 41 89 c4 e9 56 ff ff ff 41 8b 46 28 <0f> 0d 0c 03 0f 1f 44 00 00 66 90 49 83 7e 48 00 74 05 45 31 ff eb
RSP: 0018:ffffc90000a08120 EFLAGS: 00000246
RAX: 0000000000000078 RBX: ffff8880618b73c0 RCX: 0000000000ed3041
RDX: 0000000000ed3039 RSI: ffffffff92a30190 RDI: ffffffff8e259860
RBP: 0000000000000820 R08: ffff88807d10bc00 R09: 0000000000000003
R10: 0000000000000002 R11: 0000000000000100 R12: 00000000ffffffff
R13: ffff8880618b7280 R14: ffff88801e6bc8c0 R15: 0000000000ed3039
FS: 0000000000000000(0000) GS:ffff888125d12000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb18562ecb0 CR3: 000000000df36000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000009123
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
skb_clone+0x212/0x3a0 net/core/skbuff.c:2049
deliver_clone net/bridge/br_forward.c:125 [inline]
br_flood+0x414/0x6a0 net/bridge/br_forward.c:249
br_handle_frame_finish+0x14b4/0x19b0 net/bridge/br_input.c:221
br_nf_hook_thresh+0x3c3/0x4a0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x948/0xd00 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:283 [inline]
br_handle_frame+0x982/0x14c0 net/bridge/br_input.c:434
__netif_receive_skb_core+0x10b6/0x4020 net/core/dev.c:5878
__netif_receive_skb_one_core net/core/dev.c:5989 [inline]
__netif_receive_skb+0x72/0x380 net/core/dev.c:6104
process_backlog+0x60e/0x14f0 net/core/dev.c:6456
__napi_poll+0xc4/0x360 net/core/dev.c:7506
napi_poll net/core/dev.c:7569 [inline]
net_rx_action+0x707/0xe30 net/core/dev.c:7696
handle_softirqs+0x283/0x870 kernel/softirq.c:579
do_softirq+0xec/0x180 kernel/softirq.c:480
__local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407
local_bh_enable include/linux/bottom_half.h:33 [inline]
fpregs_unlock arch/x86/include/asm/fpu/api.h:77 [inline]
kernel_fpu_end+0xd2/0x120 arch/x86/kernel/fpu/core.c:479
blake2s_compress+0x5f/0xd0 lib/crypto/x86/blake2s-glue.c:46
blake2s_update+0x14b/0x450 lib/crypto/blake2s.c:33
hmac+0x1b6/0x330 drivers/net/wireguard/noise.c:324
kdf drivers/net/wireguard/noise.c:360 [inline]
mix_dh drivers/net/wireguard/noise.c:413 [inline]
wg_noise_handshake_create_response+0x462/0x970 drivers/net/wireguard/noise.c:702
wg_packet_send_handshake_response+0xf6/0x2d0 drivers/net/wireguard/send.c:94
wg_receive_handshake_packet drivers/net/wireguard/receive.c:154 [inline]
wg_packet_handshake_receive_worker+0x627/0xfb0 drivers/net/wireguard/receive.c:213
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/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