INFO: task kworker/R-ipv6_:3172 blocked for more than 149 seconds. Not tainted 6.14.0-next-20250401-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/R-ipv6_ state:D stack:24760 pid:3172 tgid:3172 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: ipv6_addrconf addrconf_dad_work Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746 rtnl_net_lock include/linux/rtnetlink.h:130 [inline] addrconf_dad_work+0x110/0x16a0 net/ipv6/addrconf.c:4190 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 rescuer_thread+0x662/0x1020 kernel/workqueue.c:3496 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 2 locks held by kworker/0:0/9: 8 locks held by kworker/0:1/10: 3 locks held by kworker/u8:0/12: 3 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8ed3e000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3e000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3e000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764 6 locks held by kworker/R-write/33: #0: ffff88801ea84948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801ea84948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000aa7be0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000aa7be0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff88814d9940e0 (&type->s_umount_key#32){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff88814d996b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages_down_read fs/ext4/ext4.h:1778 [inline] #3: ffff88814d996b98 (&sbi->s_writepages_rwsem){++++}-{0:0}, at: ext4_writepages+0x218/0x450 fs/ext4/inode.c:2827 #4: ffff888034258950 (jbd2_handle){++++}-{0:0}, at: start_this_handle+0x1ec4/0x21a0 fs/jbd2/transaction.c:444 #5: ffff88807a44a080 (&ei->i_data_sem){++++}-{4:4}, at: ext4_map_blocks+0x7d3/0x1a70 fs/ext4/inode.c:704 3 locks held by kworker/u8:2/36: 4 locks held by kworker/1:1/47: #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000b87c60 (reg_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000b87c60 (reg_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900fdd08 (rtnl_mutex){+.+.}-{4:4}, at: reg_todo+0x1c/0x8d0 net/wireless/reg.c:3219 #3: ffff888025430768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6092 [inline] #3: ffff888025430768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_process_self_managed_hints+0xb9/0x1c0 net/wireless/reg.c:3209 3 locks held by kworker/u8:3/53: 3 locks held by kworker/u8:4/62: 2 locks held by kworker/0:1H/1068: #0: ffff88801ceaed48 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801ceaed48 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90003f1fc60 ((work_completion)(&q->timeout_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003f1fc60 ((work_completion)(&q->timeout_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 3 locks held by kworker/u8:5/1089: 3 locks held by kworker/u8:6/1108: 3 locks held by kworker/u8:7/1157: 7 locks held by kworker/0:2/1208: 3 locks held by kworker/R-ipv6_/3172: #0: ffff88814dab9948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88814dab9948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000c1e7be0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000c1e7be0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900fdd08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff900fdd08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x110/0x16a0 net/ipv6/addrconf.c:4190 2 locks held by kworker/R-bat_e/3402: 5 locks held by kworker/u9:1/5152: #0: ffff8880273c3948 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8880273c3948 ((wq_completion)hci3){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000fcc7c60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000fcc7c60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff888032a60d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:331 #3: ffff888032a60078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x1f1/0xeb0 net/bluetooth/hci_sync.c:5597 #4: ffffffff902639e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2051 [inline] #4: ffffffff902639e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x15d/0x300 net/bluetooth/hci_conn.c:1269 2 locks held by syslogd/5194: 1 lock held by klogd/5201: 2 locks held by udevd/5212: 1 lock held by dhcpcd/5505: 1 lock held by dhcpcd/5506: 2 locks held by getty/5594: #0: ffff88803609a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/5828: 4 locks held by kworker/1:3/5842: 7 locks held by kworker/u9:2/5843: #0: ffff8880358c8948 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff8880358c8948 ((wq_completion)hci2){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90003fcfc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003fcfc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff88802857cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:331 #3: ffff88802857c078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x1f1/0xeb0 net/bluetooth/hci_sync.c:5597 #4: ffffffff902639e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2051 [inline] #4: ffffffff902639e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x15d/0x300 net/bluetooth/hci_conn.c:1269 #5: ffff888027eb3338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x71/0x690 net/bluetooth/l2cap_core.c:1761 #6: ffffffff8ed43538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #6: ffffffff8ed43538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x454/0x830 kernel/rcu/tree_exp.h:998 2 locks held by syz-executor/5845: 5 locks held by syz-executor/5847: 6 locks held by kworker/1:4/5854: 5 locks held by kworker/u9:6/5856: 5 locks held by kworker/u9:7/5857: #0: ffff888028b09148 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888028b09148 ((wq_completion)hci1){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc900040cfc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900040cfc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff888034f48d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:331 #3: ffff888034f48078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x1f1/0xeb0 net/bluetooth/hci_sync.c:5597 #4: ffffffff902639e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_connect_cfm include/net/bluetooth/hci_core.h:2051 [inline] #4: ffffffff902639e8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x15d/0x300 net/bluetooth/hci_conn.c:1269 2 locks held by kworker/0:3/5894: 3 locks held by kworker/1:6/5895: #0: ffff88801b081d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b081d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000428fc60 ((crda_timeout).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000428fc60 ((crda_timeout).work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff900fdd08 (rtnl_mutex){+.+.}-{4:4}, at: crda_timeout_work+0x15/0x50 net/wireless/reg.c:541 2 locks held by kworker/0:6/5925: 4 locks held by kworker/0:7/5929: 1 lock held by syz.4.12/5962: #0: ffff8880320740e0 (&type->s_umount_key#48/1){+.+.}-{4:4}, at: alloc_super+0x221/0x9d0 fs/super.c:344 3 locks held by kworker/u8:8/5963: 3 locks held by kworker/u8:9/5964: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-next-20250401-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:437 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 1208 Comm: kworker/0:2 Not tainted 6.14.0-next-20250401-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: mld mld_dad_work RIP: 0010:check_preemption_disabled+0x52/0x120 lib/smp_processor_id.c:55 Code: 34 be 38 07 a9 ff ff ff 7f 74 24 65 49 8b 04 24 48 3b 44 24 08 0f 85 cc 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f cc cc cc cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 RSP: 0018:ffffc900000060f8 EFLAGS: 00000282 RAX: 0000000000000000 RBX: ffffffff9368d020 RCX: ffff888027881e00 RDX: dffffc0000000000 RSI: ffffffff8ca1d5e0 RDI: ffffffff8ca1d5a0 RBP: ffffffff816e0218 R08: ffffc90000007970 R09: 0000000000000000 R10: ffffc900000062b0 R11: fffff52000000c58 R12: ffffc90000006270 R13: dffffc0000000000 R14: ffffc90000007980 R15: ffffffff8ed3e000 FS: 0000000000000000(0000) GS:ffff888124f93000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc35b9aff8 CR3: 0000000063b08000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:736 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4e/0x3e0 kernel/locking/lockdep.c:5877 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x1a9f/0x23b0 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2389 [inline] slab_free mm/slub.c:4646 [inline] kmem_cache_free+0x197/0x410 mm/slub.c:4748 br_nf_dev_queue_xmit+0x4cb/0x2560 net/bridge/br_netfilter_hooks.c:-1 NF_HOOK+0x6bf/0x780 include/linux/netfilter.h:314 br_nf_post_routing+0xa28/0xe80 net/bridge/br_netfilter_hooks.c:969 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc8/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x2ac/0x460 include/linux/netfilter.h:312 br_forward_finish+0xd8/0x130 net/bridge/br_forward.c:66 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:-1 [inline] br_nf_forward_finish+0xb50/0xfb0 net/bridge/br_netfilter_hooks.c:665 NF_HOOK+0x6bf/0x780 include/linux/netfilter.h:314 br_nf_forward_ip+0x61e/0x7b0 net/bridge/br_netfilter_hooks.c:719 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc8/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x2ac/0x460 include/linux/netfilter.h:312 __br_forward+0x46a/0x640 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xb3/0x150 net/bridge/br_forward.c:190 br_flood+0x2e4/0x680 net/bridge/br_forward.c:237 br_handle_frame_finish+0x185b/0x1f60 net/bridge/br_input.c:220 br_nf_hook_thresh+0x482/0x5a0 net/bridge/br_netfilter_hooks.c:1170 br_nf_pre_routing_finish_ipv6+0xaa3/0xdd0 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x397/0x790 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0x9fa/0x1530 net/bridge/br_input.c:433 __netif_receive_skb_core+0x155a/0x4bb0 net/core/dev.c:5777 __netif_receive_skb_one_core net/core/dev.c:5889 [inline] __netif_receive_skb+0x130/0x670 net/core/dev.c:6004 process_backlog+0x664/0x15c0 net/core/dev.c:6356 __napi_poll+0xcb/0x480 net/core/dev.c:7328 napi_poll net/core/dev.c:7392 [inline] net_rx_action+0x89d/0x1240 net/core/dev.c:7514 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579 do_softirq+0x11f/0x1e0 kernel/softirq.c:480 __local_bh_enable_ip+0x1be/0x200 kernel/softirq.c:407 local_bh_enable include/linux/bottom_half.h:33 [inline] ip6t_do_table+0x1695/0x18c0 net/ipv6/netfilter/ip6_tables.c:375 ip6t_mangle_out net/ipv6/netfilter/ip6table_mangle.c:49 [inline] ip6table_mangle_hook+0x265/0x7a0 net/ipv6/netfilter/ip6table_mangle.c:72 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc8/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x309/0x440 include/linux/netfilter.h:312 mld_sendpack+0x84a/0xdc0 net/ipv6/mcast.c:1868 mld_dad_work+0x44/0x500 net/ipv6/mcast.c:2308 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245