INFO: task syz.5.3991:25884 blocked for more than 145 seconds. Not tainted 6.16.0-syzkaller-11489-gd2eedaa3909b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.3991 state:D stack:29112 pid:25884 tgid:25880 ppid:21884 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7058 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115 rwsem_down_write_slowpath+0x524/0x1310 kernel/locking/rwsem.c:1185 __down_write_common kernel/locking/rwsem.c:1317 [inline] __down_write kernel/locking/rwsem.c:1326 [inline] down_write+0x1d6/0x200 kernel/locking/rwsem.c:1591 tty_change_softcar drivers/tty/tty_ioctl.c:743 [inline] tty_mode_ioctl+0x9ed/0xd30 drivers/tty/tty_ioctl.c:886 n_tty_ioctl_helper+0x4b/0x2b0 drivers/tty/tty_ioctl.c:982 n_tty_ioctl+0x7f/0x370 drivers/tty/n_tty.c:2509 tty_ioctl+0x700/0x1680 drivers/tty/tty_io.c:2801 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:598 [inline] __se_sys_ioctl fs/ioctl.c:584 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x490 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc48918eb69 RSP: 002b:00007fc486ff6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fc4893b6160 RCX: 00007fc48918eb69 RDX: 0000000000000003 RSI: 000000000000541a RDI: 0000000000000003 RBP: 00007fc489211df1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007fc4893b6160 R15: 00007ffd69ce2258 Showing all locks held in the system: 1 lock held by kthreadd/2: 1 lock held by kworker/R-kvfre/6: #0: ffffffff8e478268 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_attach_to_pool+0x27/0x420 kernel/workqueue.c:2676 3 locks held by kworker/u8:0/12: 1 lock held by kworker/R-mm_pe/14: #0: ffffffff8e478268 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2734 [inline] #0: ffffffff8e478268 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 1 lock held by khungtaskd/31: #0: ffffffff8e5c10a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e5c10a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e5c10a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 1 lock held by kworker/R-write/33: 3 locks held by kworker/1:1/43: 3 locks held by kworker/u8:5/233: 3 locks held by kworker/R-ipv6_/3204: #0: ffff88814c5b9148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc9000b737ca8 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff9037ee08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff9037ee08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734 1 lock held by kworker/R-bat_e/3428: #0: ffffffff8e478268 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2734 [inline] #0: ffffffff8e478268 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 2 locks held by klogd/5224: 3 locks held by udevd/5235: 3 locks held by dhcpcd/5529: 5 locks held by dhcpcd/5530: 1 lock held by crond/5607: 3 locks held by syz-executor/5851: 1 lock held by kworker/1:4/5918: 3 locks held by kworker/u8:23/10321: 5 locks held by kworker/u8:27/10325: 3 locks held by kworker/u8:30/10329: 3 locks held by kworker/1:2/14868: 2 locks held by getty/16044: #0: ffff8880313df0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900032d42f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 3 locks held by kworker/1:3/16388: 4 locks held by kworker/0:3/16576: 2 locks held by kworker/u8:1/17813: 3 locks held by kworker/u8:2/18155: 3 locks held by kworker/u8:3/21297: 3 locks held by kworker/u8:4/21606: 3 locks held by kworker/0:0/21689: 4 locks held by kworker/0:1/21691: #0: ffff88801b882148 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90003f5fd10 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffffffff9037ee08 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x83/0x1180 net/wireless/reg.c:2483 #3: ffff888027af8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6212 [inline] #3: ffff888027af8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_leave_invalid_chans net/wireless/reg.c:2471 [inline] #3: ffff888027af8768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_check_chans_work+0x10d/0x1180 net/wireless/reg.c:2486 5 locks held by kworker/1:0/21980: 1 lock held by kworker/R-wg-cr/22037: #0: ffffffff8e478268 (wq_pool_attach_mutex){+.+.}-{4:4}, at: worker_detach_from_pool kernel/workqueue.c:2734 [inline] #0: ffffffff8e478268 (wq_pool_attach_mutex){+.+.}-{4:4}, at: rescuer_thread+0x839/0xea0 kernel/workqueue.c:3529 2 locks held by syz-executor/22113: 3 locks held by kworker/1:6/22274: 6 locks held by syz.1.3986/25857: 6 locks held by syz.5.3991/25883: 2 locks held by syz.5.3991/25884: #0: ffff88807ce310a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffff88807ce312e8 (&tty->termios_rwsem){++++}-{4:4}, at: tty_change_softcar drivers/tty/tty_ioctl.c:743 [inline] #1: ffff88807ce312e8 (&tty->termios_rwsem){++++}-{4:4}, at: tty_mode_ioctl+0x9ed/0xd30 drivers/tty/tty_ioctl.c:886 3 locks held by kworker/u8:6/25885: 3 locks held by kworker/0:2/25886: #0: ffff88805c10c948 ((wq_completion)wg-kex-wg1#22){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90010d97d10 ((work_completion)(&({ do { const void *__vpp_verify = (typeof((worker) + 0))((void *)0); (void)__vpp_verify; } while (0); ({ unsigned long __ptr; __asm__ ("" : "=r"(__ptr) : "0"((__typeof__(*((worker))) *)(( unsigned long)((worker))))); (typeof((__typeof__(*((worker))) *)(( unsigned long)((worker))))) (__ptr + (((__per_cpu_offset[(cpu)])))); }); })->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff88805c1ce648 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_begin_session+0x30/0xe80 drivers/net/wireguard/noise.c:822 2 locks held by kworker/u8:7/25887: 4 locks held by kworker/u8:8/25888: #0: ffff888055057948 ((wq_completion)wg-kex-wg0#21){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3211 #1: ffffc90010e57d10 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3212 #2: ffff888032f1d308 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0xec/0x650 drivers/net/wireguard/noise.c:529 #3: ffff88805c1cc890 (&handshake->lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x100/0x650 drivers/net/wireguard/noise.c:530 1 lock held by dhcpcd/25889: 4 locks held by kworker/u8:9/25890: 4 locks held by kworker/u8:10/25891: 2 locks held by dhcpcd/25893: #0: ffff888076238258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline] #0: ffff888076238258 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x2c/0xf60 net/packet/af_packet.c:3251 #1: ffffffff8e5cc638 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-syzkaller-11489-gd2eedaa3909b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/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+0xf0e/0x1260 kernel/hung_task.c:491 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 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: 10325 Comm: kworker/u8:27 Not tainted 6.16.0-syzkaller-11489-gd2eedaa3909b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline] RIP: 0010:lock_acquire kernel/locking/lockdep.c:5869 [inline] RIP: 0010:lock_acquire+0x14f/0x350 kernel/locking/lockdep.c:5825 Code: 00 00 85 d2 0f 85 8c 00 00 00 9c 8f 04 24 fa 48 c7 c7 88 81 f3 8d e8 e0 6f f7 09 45 89 e0 89 e9 44 89 ea 65 ff 05 f9 ac 3d 12 <48> 81 24 24 00 02 00 00 44 89 f6 48 89 df 6a 00 6a 00 6a 00 ff b4 RSP: 0018:ffffc90000006a40 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffffffff8e5c10a0 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff8df38188 RDI: ffffffff8c15ee00 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000007 R11: 000000000009606d R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881246d3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffcd2dc2f80 CR3: 000000007b870000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2417 [inline] slab_free mm/slub.c:4680 [inline] kmem_cache_free+0x2d1/0x4d0 mm/slub.c:4782 __skb_ext_put+0x102/0x2c0 net/core/skbuff.c:7153 skb_ext_put include/linux/skbuff.h:4869 [inline] skb_ext_put include/linux/skbuff.h:4866 [inline] skb_release_head_state+0x1c2/0x290 net/core/skbuff.c:1143 skb_release_all net/core/skbuff.c:1149 [inline] __kfree_skb net/core/skbuff.c:1165 [inline] sk_skb_reason_drop+0xeb/0x1a0 net/core/skbuff.c:1203 kfree_skb_reason include/linux/skbuff.h:1275 [inline] kfree_skb include/linux/skbuff.h:1284 [inline] ip6_mc_input+0x774/0xeb0 net/ipv6/ip6_input.c:593 dst_input include/net/dst.h:471 [inline] dst_input include/net/dst.h:469 [inline] ip6_rcv_finish+0x3df/0x580 net/ipv6/ip6_input.c:79 ip_sabotage_in+0x21b/0x290 net/bridge/br_netfilter_hooks.c:993 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623 nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:273 NF_HOOK include/linux/netfilter.h:316 [inline] ipv6_rcv+0xa4/0x650 net/ipv6/ip6_input.c:311 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:5979 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6092 netif_receive_skb_internal net/core/dev.c:6178 [inline] netif_receive_skb+0x137/0x7b0 net/core/dev.c:6237 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_pass_frame_up+0x346/0x490 net/bridge/br_input.c:70 br_handle_frame_finish+0xf5a/0x1ca0 net/bridge/br_input.c:227 br_nf_hook_thresh+0x307/0x410 net/bridge/br_netfilter_hooks.c:1170 br_nf_pre_routing_finish_ipv6+0x76a/0xfb0 net/bridge/br_netfilter_ipv6.c:154 NF_HOOK include/linux/netfilter.h:318 [inline] br_nf_pre_routing_ipv6+0x3cd/0x8c0 net/bridge/br_netfilter_ipv6.c:184 br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:508 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_bridge_pre net/bridge/br_input.c:283 [inline] br_handle_frame+0xad8/0x14b0 net/bridge/br_input.c:434 __netif_receive_skb_core.constprop.0+0xa22/0x48c0 net/core/dev.c:5866 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:5977 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6092 process_backlog+0x442/0x15e0 net/core/dev.c:6444 __napi_poll.constprop.0+0xb7/0x550 net/core/dev.c:7497 napi_poll net/core/dev.c:7560 [inline] net_rx_action+0xa9f/0xfe0 net/core/dev.c:7687 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 do_softirq kernel/softirq.c:480 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:467 __local_bh_enable_ip+0x100/0x120 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+0x5e/0x70 arch/x86/kernel/fpu/core.c:479 blake2s_compress+0x7f/0xe0 lib/crypto/x86/blake2s-glue.c:46 blake2s_update+0xef/0x360 lib/crypto/blake2s.c:33 hmac.constprop.0+0x32a/0x420 drivers/net/wireguard/noise.c:332 kdf.constprop.0+0x14b/0x280 drivers/net/wireguard/noise.c:367 mix_precomputed_dh drivers/net/wireguard/noise.c:426 [inline] wg_noise_handshake_create_initiation+0x3b0/0x650 drivers/net/wireguard/noise.c:560 wg_packet_send_handshake_initiation+0x19a/0x360 drivers/net/wireguard/send.c:34 wg_packet_handshake_send_worker+0x1c/0x30 drivers/net/wireguard/send.c:51 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245