INFO: task kworker/u8:8:6782 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:8 state:D stack:20616 pid:6782 tgid:6782 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4206 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task kworker/u8:24:9758 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:24 state:D stack:21208 pid:9758 tgid:9758 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_unbound linkwatch_event Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820 linkwatch_event+0xe/0x60 net/core/link_watch.c:313 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task kworker/0:0:6094 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:0 state:D stack:20680 pid:6094 tgid:6094 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events netdev_rx_mode_work Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820 netdev_rx_mode_work+0x19/0x3c0 net/core/dev_addr_lists.c:1312 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 2 locks held by kthreadd/2: 4 locks held by kworker/R-netns/8: #0: ffff88801be86140 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801be86140 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc900000d7c00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc900000d7c00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8fdb91a8 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673 #3: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] #3: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: ops_undo_list+0x2a4/0x940 net/core/net_namespace.c:248 1 lock held by kdevtmpfs/26: 1 lock held by khungtaskd/30: #0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cca0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:5/94: 3 locks held by kworker/0:2/808: 3 locks held by kworker/1:2/997: 6 locks held by kworker/R-bat_e/3230: 3 locks held by kworker/u8:7/3365: 1 lock held by klogd/4986: 1 lock held by udevd/4997: 1 lock held by dhcpcd/5291: 5 locks held by dhcpcd/5292: 3 locks held by kworker/0:3/5363: #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000370fc40 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000370fc40 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 2 locks held by getty/5388: #0: ffff888031a160a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 2 locks held by syz-executor/5615: 5 locks held by kworker/0:8/5748: 3 locks held by kworker/u8:8/6782: #0: ffff8880310be940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff8880310be940 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc900038ffc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc900038ffc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x11e/0x14c0 net/ipv6/addrconf.c:4206 3 locks held by kworker/u8:10/6784: 3 locks held by kworker/u8:15/6970: 2 locks held by kworker/u8:19/6977: 2 locks held by kworker/u8:23/9757: 3 locks held by kworker/u8:24/9758: #0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801ae84140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000e967c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000e967c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 3 locks held by kworker/0:10/14543: 3 locks held by kworker/1:10/22775: #0: ffff888021a93140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff888021a93140 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc9000551fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc9000551fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff888029f111d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff888029f111d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 5 locks held by kworker/u8:1/27166: 3 locks held by syz-executor/5510: 3 locks held by kworker/0:0/6094: #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88813fe43140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc900034afc40 (rx_mode_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc900034afc40 (rx_mode_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8fdc7e80 (rtnl_mutex){+.+.}-{4:4}, at: netdev_rx_mode_work+0x19/0x3c0 net/core/dev_addr_lists.c:1312 2 locks held by syz-executor/8401: 4 locks held by udevd/12418: #0: ffff888048e45ab8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183 #1: ffff888055950480 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff88803da523c8 (kn->active#31){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88803da523c8 (kn->active#31){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff88803b4491d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline] #3: ffff88803b4491d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 2 locks held by udevd/12446: 1 lock held by udevd/12449: 4 locks held by udevd/12452: 6 locks held by kworker/0:1/15154: 2 locks held by syz.5.6991/25229: 2 locks held by syz.8.7011/25305: 1 lock held by syz.8.7012/25309: 1 lock held by syz.8.7012/25311: 2 locks held by syz.8.7012/25312: 3 locks held by kworker/u8:0/25322: 2 locks held by kworker/1:1/25327: 1 lock held by kworker/u8:19/25331: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: 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:162 [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:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 3230 Comm: kworker/R-bat_e Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:__sanitizer_cov_trace_switch+0x100/0x130 kernel/kcov.c:-1 Code: f3 48 c1 e3 05 4c 8d 63 28 4d 39 fc 77 9d 49 ff c6 4d 89 33 49 89 4c 1b 08 4d 89 54 1b 10 49 89 7c 1b 18 49 89 54 1b 20 eb 81 <5b> 41 5c 41 5e 41 5f c3 cc cc cc cc cc b9 05 00 00 00 48 85 c0 0f RSP: 0018:ffffc90000006ad8 EFLAGS: 00000246 RAX: 0000000000000002 RBX: 0000000000000008 RCX: 0000000000000003 RDX: ffffffff897b2df1 RSI: ffffffff8fdbe5e0 RDI: 0000000000000008 RBP: ffffc90000006c38 R08: ffff888031b31f00 R09: 0000000000000002 R10: 000000000000a888 R11: 0000000000000100 R12: 0000052e401d4c69 R13: dffffc0000000000 R14: ffff88806f799a00 R15: 0000000000000008 FS: 0000000000000000(0000) GS:ffff88812529e000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000192030 CR3: 0000000030b0a000 CR4: 00000000003526f0 Call Trace: skb_vlan_tagged_multi include/linux/if_vlan.h:777 [inline] vlan_features_check include/linux/if_vlan.h:803 [inline] dflt_features_check net/core/dev.c:3769 [inline] netif_skb_features+0xbd1/0x1480 net/core/dev.c:3871 validate_xmit_skb+0xa0/0x14a0 net/core/dev.c:4027 validate_xmit_skb_list+0x84/0x120 net/core/dev.c:4089 sch_direct_xmit+0xdf/0x4c0 net/sched/sch_generic.c:357 qdisc_restart net/sched/sch_generic.c:437 [inline] __qdisc_run+0xa83/0x1560 net/sched/sch_generic.c:445 qdisc_run include/net/pkt_sched.h:120 [inline] __dev_xmit_skb net/core/dev.c:4292 [inline] __dev_queue_xmit+0x1d26/0x3950 net/core/dev.c:4831 dev_queue_xmit include/linux/netdevice.h:3418 [inline] neigh_hh_output include/net/neighbour.h:544 [inline] neigh_output include/net/neighbour.h:558 [inline] ip_finish_output2+0xc68/0x1070 net/ipv4/ip_output.c:237 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x29f/0x450 net/ipv4/ip_output.c:438 synproxy_send_client_synack+0x8c1/0xe30 net/netfilter/nf_synproxy_core.c:487 nft_synproxy_eval_v4+0x34a/0x4e0 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x305/0x580 net/netfilter/nft_synproxy.c:142 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x48d/0x1ae0 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6202 [inline] __netif_receive_skb net/core/dev.c:6315 [inline] process_backlog+0xaa3/0x1950 net/core/dev.c:6666 __napi_poll+0xae/0x340 net/core/dev.c:7733 napi_poll net/core/dev.c:7796 [inline] net_rx_action+0x627/0xf70 net/core/dev.c:7953 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_local_purge+0x2a7/0x340 net/batman-adv/translation-table.c:1355 batadv_tt_purge+0x35/0x9e0 net/batman-adv/translation-table.c:3549 process_one_work kernel/workqueue.c:3314 [inline] process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397 rescuer_thread+0x827/0x1130 kernel/workqueue.c:3621 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245