INFO: task syz.4.3782:26827 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.4.3782 state:D stack:28936 pid:26827 tgid:26826 ppid:23796 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7005
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7062
__mutex_lock_common kernel/locking/mutex.c:692 [inline]
__mutex_lock+0xc9a/0x1b90 kernel/locking/mutex.c:776
register_nexthop_notifier+0x1b/0x70 net/ipv4/nexthop.c:3976
ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137
setup_net+0x118/0x3a0 net/core/net_namespace.c:446
copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:581
create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:130
unshare_nsproxy_namespaces+0xc3/0x1f0 kernel/nsproxy.c:226
ksys_unshare+0x473/0xad0 kernel/fork.c:3174
__do_sys_unshare kernel/fork.c:3245 [inline]
__se_sys_unshare kernel/fork.c:3243 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:3243
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb302b9c799
RSP: 002b:00007fb303a36028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007fb302e15fa0 RCX: 00007fb302b9c799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000040000080
RBP: 00007fb302c32c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb302e16038 R14: 00007fb302e15fa0 R15: 00007ffed9cc3328
Showing all locks held in the system:
1 lock held by pool_workqueue_/3:
#0: ffffffff8e7f2ff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343
2 locks held by kworker/0:0/9:
3 locks held by kworker/0:1/10:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e73e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e73e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e73e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by kworker/0:3/5871:
3 locks held by kworker/u10:0/12507:
3 locks held by kworker/u10:2/12511:
2 locks held by kworker/u10:4/12539:
3 locks held by kworker/u10:5/12616:
2 locks held by getty/16467:
#0: ffff8880336210a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900064cf2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
3 locks held by kworker/0:4/19127:
3 locks held by kworker/u11:4/19242:
3 locks held by kworker/u10:1/19596:
3 locks held by kworker/u10:8/22545:
3 locks held by kworker/u10:9/22546:
3 locks held by kworker/u10:10/22547:
3 locks held by kworker/u10:12/22550:
3 locks held by kworker/u10:13/22551:
#0: ffff8880334d1148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
#1: ffffc90004677d08 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
#2: ffffffff90613da8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff90613da8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4738
3 locks held by kworker/u10:14/22552:
3 locks held by kworker/u10:16/22554:
3 locks held by kworker/u10:17/22557:
4 locks held by kworker/u10:18/22558:
4 locks held by kworker/u10:19/22559:
#0: ffff8880473c0148 ((wq_completion)wg-kex-wg2#15){+.+.}-{0:0}, at: process_one_work+0x1287/0x1920 kernel/workqueue.c:3250
#1: ffffc90004617d08 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x93c/0x1920 kernel/workqueue.c:3251
#2: ffff88805b8fd348 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0xec/0x610 drivers/net/wireguard/noise.c:529
#3: ffff88807d5c8338 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x100/0x610 drivers/net/wireguard/noise.c:530
3 locks held by kworker/u10:22/22562:
3 locks held by kworker/u10:23/22563:
3 locks held by kworker/u10:25/22950:
1 lock held by syz.1.3211/23889:
#0: ffffffff90613da8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff90613da8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
3 locks held by kworker/0:2/23964:
4 locks held by kworker/u10:27/25140:
3 locks held by kworker/u10:28/25143:
3 locks held by kworker/u10:29/25144:
4 locks held by kworker/u10:30/25145:
4 locks held by kworker/u10:32/25147:
3 locks held by kworker/u10:33/25148:
4 locks held by kworker/u10:36/25308:
1 lock held by syz.0.3775/26803:
#0: ffffffff90613da8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff90613da8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
1 lock held by syz.3.3776/26807:
#0: ffffffff90613da8 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff90613da8 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x38/0x220 drivers/net/tun.c:3436
2 locks held by syz.4.3782/26827:
#0: ffffffff905fb550 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x451/0x7c0 net/core/net_namespace.c:577
#1: ffffffff90613da8 (rtnl_mutex){+.+.}-{4:4}, at: register_nexthop_notifier+0x1b/0x70 net/ipv4/nexthop.c:3976
2 locks held by kworker/0:5/26830:
1 lock held by syz-executor/26853:
#0: ffffffff90613da8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff90613da8 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x30c/0x18b0 net/ipv4/devinet.c:978
2 locks held by kworker/0:6/26861:
2 locks held by kworker/0:7/26863:
3 locks held by kworker/0:8/26864:
1 lock held by syz-executor/26879:
#0: ffff888089690ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_open+0x22/0xb0 net/bluetooth/hci_core.c:429
2 locks held by dhcpcd/26887:
#0: ffff888028184260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1709 [inline]
#0: ffff888028184260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf50 net/packet/af_packet.c:3197
#1: ffffffff8e7f2ff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311
=============================================
NMI backtrace for cpu 1
CPU: 1 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 02/12/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 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: 25148 Comm: kworker/u10:33 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: bat_events batadv_tt_purge
RIP: 0010:rcu_is_watching+0x80/0xc0 kernel/rcu/tree.c:753
Code: 89 da 48 c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 24 8b 03 c1 e8 02 83 e0 01 65 ff 0d a0 87 20 12 <74> 07 5b 5d e9 47 b3 a3 09 e8 d2 7a 89 ff 5b 5d c3 cc cc cc cc 48
RSP: 0018:ffffc900000077f0 EFLAGS: 00000282
RAX: 0000000000000001 RBX: ffff8880b8433ca8 RCX: ffffffff8a65e4bf
RDX: 0000000000000000 RSI: ffffffff8c1b0320 RDI: ffffffff8e12c8e0
RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888059b58800
R13: 0000000000000001 R14: ffff8880361bbe5c R15: ffffc90000007910
FS: 0000000000000000(0000) GS:ffff88812434c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3290fff8 CR3: 000000000e598000 CR4: 00000000003526f0
Call Trace:
rcu_read_unlock include/linux/rcupdate.h:879 [inline]
net_generic+0x191/0x2a0 include/net/netns/generic.h:48
br_nf_pre_routing+0x157/0x1550 net/bridge/br_netfilter_hooks.c:496
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0xcdd/0x1520 net/bridge/br_input.c:442
__netif_receive_skb_core.constprop.0+0x6c5/0x3550 net/core/dev.c:6051
__netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6162
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6277
process_backlog+0x37a/0x1580 net/core/dev.c:6628
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7692
napi_poll net/core/dev.c:7755 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7912
handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xac/0xe0 kernel/softirq.c:510
__local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:395 [inline]
batadv_tt_global_purge net/batman-adv/translation-table.c:2250 [inline]
batadv_tt_purge+0x25d/0xbd0 net/batman-adv/translation-table.c:3510
process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275
process_scheduled_works kernel/workqueue.c:3358 [inline]
worker_thread+0x5da/0xe40 kernel/workqueue.c:3439
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245