INFO: task kworker/1:3:5865 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:3 state:D stack:23352 pid:5865 tgid:5865 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events console_callback Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 ___down_common+0x2d5/0x450 kernel/locking/semaphore.c:268 __down_common kernel/locking/semaphore.c:293 [inline] __down+0x20/0x30 kernel/locking/semaphore.c:303 down+0x74/0xa0 kernel/locking/semaphore.c:100 console_lock+0x5b/0xa0 kernel/printk/printk.c:2822 class_console_lock_constructor include/linux/console.h:669 [inline] console_callback+0x62/0x4c0 drivers/tty/vt/vt.c:3256 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x672/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task kworker/u8:9:6301 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:25592 pid:6301 tgid:6301 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7083 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x818/0x1060 kernel/locking/mutex.c:760 linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263 process_scheduled_works kernel/workqueue.c:3346 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x672/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by kthreadd/2: 3 locks held by kworker/0:0/9: 3 locks held by kworker/0:1/10: 4 locks held by kworker/u8:0/12: 5 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8e3c44a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c44a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c44a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:2/36: 3 locks held by kworker/u8:3/50: #0: ffff88814ccc7948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc90000bb7d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff900fa988 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff900fa988 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4734 3 locks held by kworker/u8:4/60: 4 locks held by kworker/u8:5/78: 3 locks held by kworker/0:2/911: 2 locks held by kworker/1:2/1213: 3 locks held by kworker/u8:6/1308: 3 locks held by kworker/u8:7/1314: 2 locks held by kworker/R-bat_e/3405: 1 lock held by dhcpcd/5476: 1 lock held by dhcpcd/5477: 2 locks held by getty/5569: #0: ffff88814d7c10a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5791: 1 lock held by syz-executor/5816: 2 locks held by kworker/0:4/5820: 2 locks held by kworker/1:3/5865: #0: ffff88813ff51948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc9000450fd00 (console_work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 3 locks held by kworker/0:8/5927: 3 locks held by kworker/u8:8/6096: 3 locks held by kworker/u8:9/6301: #0: ffff88813ff69948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc90005957d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff900fa988 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 3 locks held by kworker/u8:10/6576: 3 locks held by kworker/u8:11/6577: 1 lock held by syz.4.544/8117: 4 locks held by syz.4.564/8176: 4 locks held by syz-executor/8204: 1 lock held by syz-executor/8224: 4 locks held by syz-executor/8237: ============================================= 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 10/02/2025 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:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c2/0x780 kernel/kthread.c:463 ret_from_fork+0x672/0x7d0 arch/x86/kernel/process.c:158 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:ip6_multipath_l3_keys.constprop.0+0x766/0xbd0 net/ipv6/route.c:2380 Code: ad f7 48 8d 7b 2c 48 ba 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 0f b6 0c 10 48 8d 43 3b 48 89 c6 48 c1 ee 03 0f b6 14 16 <48> 89 fe 83 e6 07 40 38 f1 40 0f 9e c6 84 c9 0f 95 c1 40 84 ce 0f RSP: 0018:ffffc90000a07b50 EFLAGS: 00000a06 RAX: ffffc90000a07d4b RBX: ffffc90000a07d10 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 1ffff92000140fa9 RDI: ffffc90000a07d3c RBP: ffffc90000a07c90 R08: 0000000000000005 R09: 0000000000000003 R10: 0000000000000084 R11: 0000000000000000 R12: ffff888034835050 R13: ffffc90000a07bf8 R14: ffff88815162f780 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124adf000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdb89665f3a CR3: 0000000077e3b000 CR4: 00000000003526f0 Call Trace: rt6_multipath_hash+0x5f5/0x1920 net/ipv6/route.c:2522 ip6_route_input+0xacd/0xc70 net/ipv6/route.c:2639 ip6_rcv_finish_core.constprop.0+0x1a0/0x5d0 net/ipv6/ip6_input.c:66 ip6_rcv_finish+0x130/0x580 net/ipv6/ip6_input.c:77 ip_sabotage_in+0x21b/0x290 net/bridge/br_netfilter_hooks.c:990 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:623 nf_hook.constprop.0+0x424/0x750 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:6079 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6192 netif_receive_skb_internal net/core/dev.c:6278 [inline] netif_receive_skb+0x137/0x7b0 net/core/dev.c:6337 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+0x10b7/0x1ec0 net/bridge/br_input.c:235 br_nf_hook_thresh+0x307/0x410 net/bridge/br_netfilter_hooks.c:1167 br_nf_pre_routing_finish_ipv6+0x76a/0xfc0 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:291 [inline] br_handle_frame+0xad8/0x14b0 net/bridge/br_input.c:442 __netif_receive_skb_core.constprop.0+0xa22/0x4bd0 net/core/dev.c:5966 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6077 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6192 process_backlog+0x439/0x15e0 net/core/dev.c:6544 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7594 napi_poll net/core/dev.c:7657 [inline] net_rx_action+0x97f/0xef0 net/core/dev.c:7784 handle_softirqs+0x216/0x8e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: e7 75 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 f6 24 00 fb f4 0c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197de8 EFLAGS: 000002c2 RAX: 0000000001ecbfef RBX: 0000000000000001 RCX: ffffffff8b6522d9 RDX: 0000000000000000 RSI: ffffffff8db026b0 RDI: ffffffff8bf1cfc0 RBP: ffffed1003b53490 R08: 0000000000000001 R09: ffffed10170a6655 R10: ffff8880b85332ab R11: 0000000000000000 R12: 0000000000000001 R13: ffff88801da9a480 R14: ffffffff908324d0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148