INFO: task kworker/u8:4:63 blocked for more than 152 seconds.
      Not tainted 6.12.0-rc2-syzkaller-00291-g09f6b0c8904b #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:4    state:D stack:22744 pid:63    tgid:63    ppid:2      flags:0x00004000
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5322 [inline]
 __schedule+0x1843/0x4ae0 kernel/sched/core.c:6682
 __schedule_loop kernel/sched/core.c:6759 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6774
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6831
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752
 addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
3 locks held by kworker/0:0/8:
2 locks held by kworker/u8:1/12:
1 lock held by ksoftirqd/0/16:
1 lock held by khungtaskd/30:
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
3 locks held by kworker/u8:4/63:
 #0: ffff88802dce6148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff88802dce6148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc900015e7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900015e7d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffffffff8fcbfc08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196
4 locks held by kworker/1:2/1855:
1 lock held by udevd/4676:
2 locks held by getty/4979:
 #0: ffff88802e6b40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
1 lock held by syz-executor399/5233:

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

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc2-syzkaller-00291-g09f6b0c8904b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc2-syzkaller-00291-g09f6b0c8904b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:kasan_check_range+0x1be/0x290 mm/kasan/generic.c:189
Code: 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 3b 00 0f 85 a6 00 00 00 49 ff c3 48 ff cd 75 ee 5b 41 5c 41 5e 41 5f <5d> c3 cc cc cc cc 40 84 ed 75 5f f7 c5 00 ff 00 00 75 5c f7 c5 00
RSP: 0018:ffffc90000157330 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff81710ece
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff94292800
RBP: 0000000000000000 R08: ffffffff94292807 R09: 1ffffffff2852500
R10: dffffc0000000000 R11: fffffbfff2852501 R12: dffffc0000000000
R13: ffff88801beee500 R14: 784bb2a7ec10647d R15: ffff88801beee500
FS:  0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555642d1918 CR3: 000000007d364000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 hlock_class kernel/locking/lockdep.c:228 [inline]
 lookup_chain_cache_add kernel/locking/lockdep.c:3816 [inline]
 validate_chain+0x11e/0x5920 kernel/locking/lockdep.c:3872
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162
 debug_object_active_state+0x15d/0x360 lib/debugobjects.c:936
 debug_rcu_head_unqueue kernel/rcu/rcu.h:233 [inline]
 rcu_do_batch kernel/rcu/tree.c:2559 [inline]
 rcu_core+0xa21/0x17a0 kernel/rcu/tree.c:2823
 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554
 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927
 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>