INFO: task dhcpcd:5565 blocked for more than 143 seconds.
      Not tainted 6.16.0-syzkaller-06620-gae633388cae3 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:dhcpcd          state:D stack:21384 pid:5565  tgid:5565  ppid:5564   task_flags:0x400140 flags:0x00004002
Call Trace:
 <TASK>
 __schedule+0x1737/0x4d30
 schedule+0x165/0x360
 schedule_preempt_disabled+0x13/0x30
 __mutex_lock+0x7e3/0x1340
 rtnl_dumpit+0xa9/0x200
 netlink_dump+0x6e4/0xe90
 netlink_recvmsg+0x676/0xa30
 sock_recvmsg+0x22c/0x270
 ____sys_recvmsg+0x1c9/0x460
 ___sys_recvmsg+0x1b5/0x510
 __x64_sys_recvmsg+0x198/0x260
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffb70c9291e
RSP: 002b:00007ffca91e4b88 EFLAGS: 00000246 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00007ffca91e5cb0 RCX: 00007ffb70c9291e
RDX: 0000000000000000 RSI: 00007ffca91e5bd0 RDI: 0000000000000019
RBP: 00007ffca91e5c40 R08: 0000000000000000 R09: 0000000000004000
R10: 00000000000000f8 R11: 0000000000000246 R12: 0000000000000e78
R13: 00007ffca91e5bb4 R14: 00007ffca91e5bd0 R15: 00007ffca91e5bc0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/34:
 #0: ffffffff8e13c4e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180
6 locks held by kworker/u11:0/55:
 #0: ffff8881077bb948 ((wq_completion)hci4){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900007dfbc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff8881191a8dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0
 #3: ffff8881191a80b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x242/0xe30
 #4: ffffffff8f66d9c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_failed+0x165/0x310
 #5: ffff888118465b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680
3 locks held by kworker/0:2/1276:
2 locks held by getty/5646:
 #0: ffff888109e1f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70
 #1: ffffc900029062f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400
4 locks held by kworker/u8:3/5842:
 #0: ffff88801b2f6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900044cfbc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffffffff8f4fc190 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x800
 #3: ffffffff8e141f38 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730
2 locks held by kworker/u8:4/5854:
1 lock held by syz-executor/6827:
1 lock held by syz-executor/6830:
1 lock held by syz-executor/6834:
1 lock held by syz-executor/6847:
4 locks held by kworker/u11:4/6858:
 #0: ffff8881103fe948 ((wq_completion)hci5){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0
 #1: ffffc900061c7bc0 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0
 #2: ffff88802a828dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d4/0x3a0
 #3: ffff88802a8280b8 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x242/0xe30
3 locks held by syz-executor/6865:
 #0: ffff88801f7ccdc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510
 #1: ffff88801f7cc0b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330
 #2: ffffffff8f66d9c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230
3 locks held by syz-executor/6869:
 #0: ffff888111e50dc0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x510
 #1: ffff888111e500b8 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330
 #2: ffffffff8f66d9c8 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230

=============================================

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 34 Comm: khungtaskd Not tainted 6.16.0-syzkaller-06620-gae633388cae3 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250
 nmi_cpu_backtrace+0x39e/0x3d0
 nmi_trigger_cpumask_backtrace+0x17a/0x300
 watchdog+0xf93/0xfe0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5854 Comm: kworker/u8:4 Not tainted 6.16.0-syzkaller-06620-gae633388cae3 #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: bat_events batadv_tt_purge
RIP: 0010:unwind_next_frame+0x50/0x2390
Code: 48 89 d8 48 c1 e8 03 48 89 44 24 30 80 3c 28 00 74 08 48 89 df e8 00 07 b0 00 48 89 5c 24 18 49 8b 5e 48 4d 8d 6e 38 4c 89 e8 <48> c1 e8 03 48 89 44 24 58 80 3c 28 00 74 08 4c 89 ef e8 d9 06 b0
RSP: 0018:ffffc900001df898 EFLAGS: 00000246
RAX: ffffc900001df9a0 RBX: ffffffff82229ade RCX: 1cf6e8f1d39baf00
RDX: dffffc0000000000 RSI: ffffffff82229ade RDI: ffffc900001df968
RBP: dffffc0000000000 R08: ffffc900001dfa30 R09: 0000000000000000
R10: ffffc900001df9b8 R11: ffffffff81ac3450 R12: ffff888105840000
R13: ffffc900001df9a0 R14: ffffc900001df968 R15: ffffc900001df968
FS:  0000000000000000(0000) GS:ffff8881a3c80000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb9b0a44480 CR3: 00000000476d0000 CR4: 00000000000006f0
Call Trace:
 <IRQ>
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x62/0x70
 kmem_cache_free+0x18f/0x400
 sk_skb_reason_drop+0xe9/0x170
 ip6_mc_input+0x8f4/0xaf0
 ip_sabotage_in+0x1e1/0x270
 nf_hook_slow+0xc5/0x220
 NF_HOOK+0x206/0x3a0
 __netif_receive_skb+0xd3/0x380
 netif_receive_skb+0x1cb/0x790
 NF_HOOK+0xa0/0x390
 br_handle_frame_finish+0x14d1/0x19b0
 br_nf_hook_thresh+0x3c6/0x4a0
 br_nf_pre_routing_finish_ipv6+0x948/0xd00
 br_nf_pre_routing_ipv6+0x37e/0x6b0
 br_handle_frame+0x982/0x14c0
 __netif_receive_skb_core+0x10b9/0x4020
 __netif_receive_skb+0x72/0x380
 process_backlog+0x60e/0x14f0
 __napi_poll+0xc7/0x360
 net_rx_action+0x707/0xe30
 handle_softirqs+0x286/0x870
 do_softirq+0xec/0x180
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0
 batadv_tt_local_purge+0x2a7/0x340
 batadv_tt_purge+0x35/0x9e0
 process_scheduled_works+0xae1/0x17b0
 worker_thread+0x8a0/0xda0
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>
