rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=cb7c/1/0x4000000000000000 softirq=0/0 fqs=5249 rcuc=10417 jiffies(starved)
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:     5694          0           12
rcu: 	cputime:      109      52329           54   ==> 52490(ms)
rcu: 	(t=10501 jiffies g=23357 q=6221 ncpus=2)
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 8b d3 cb f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> b3 8b 95 f6 65 8b 05 dc dc fb 06 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90000157780 EFLAGS: 00000206
RAX: 38c9a55bca064d00 RBX: 0000000000000a06 RCX: 38c9a55bca064d00
RDX: 0000000000000002 RSI: ffffffff8d03a0c9 RDI: 0000000000000001
RBP: ffffc90000157810 R08: ffffffff8f1d5a37 R09: 1ffffffff1e3ab46
R10: dffffc0000000000 R11: fffffbfff1e3ab47 R12: dffffc0000000000
R13: ffffc90000157868 R14: ffff8880312f2428 R15: 1ffff9200002aef0
FS:  0000000000000000(0000) GS:ffff8881268bf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563bc858b950 CR3: 000000000d7a6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:94 [inline]
 rtlock_slowlock kernel/locking/rtmutex.c:1896 [inline]
 rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
 __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
 rt_spin_lock+0x167/0x2c0 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:44 [inline]
 advance_sched+0xca/0xc90 net/sched/sch_taprio.c:929
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x54f/0xd40 kernel/time/hrtimer.c:1825
 hrtimer_run_softirq+0x1a3/0x2e0 kernel/time/hrtimer.c:1842
 handle_softirqs+0x22f/0x710 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 run_ktimerd+0xcf/0x190 kernel/softirq.c:1043
 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 16 Comm: ktimers/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3802 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3821 [inline]
RIP: 0010:validate_chain+0x1dd/0x2140 kernel/locking/lockdep.c:3876
Code: 00 00 41 ff cc 48 ff cb f7 c1 00 60 00 00 74 c8 e9 8d 00 00 00 48 c7 c7 30 94 87 8d 4c 89 fe e8 79 cd 52 03 48 8b 14 24 eb c9 <48> 8b 48 18 4c 39 f9 0f 84 b2 00 00 00 48 8b 40 08 48 85 c0 0f 84
RSP: 0018:ffffc90000157538 EFLAGS: 00000046
RAX: ffffffff931f0df0 RBX: 0000000000039401 RCX: 0000000000040000
RDX: 0000000000000000 RSI: ffff88801ae86578 RDI: ffff88801ae85940
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8af90bd4
R10: dffffc0000000000 R11: fffffbfff1e3ab47 R12: 0000000000000000
R13: ffff88801ae86460 R14: ffff88801ae86578 R15: ff0ab14204b24bab
FS:  0000000000000000(0000) GS:ffff8881268bf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000563bc858b950 CR3: 000000000d7a6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa7/0xf0 kernel/locking/spinlock.c:162
 rtlock_slowlock kernel/locking/rtmutex.c:1894 [inline]
 rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
 __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
 rt_spin_lock+0x144/0x2c0 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:44 [inline]
 advance_sched+0xca/0xc90 net/sched/sch_taprio.c:929
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x54f/0xd40 kernel/time/hrtimer.c:1825
 hrtimer_run_softirq+0x1a3/0x2e0 kernel/time/hrtimer.c:1842
 handle_softirqs+0x22f/0x710 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 run_ktimerd+0xcf/0x190 kernel/softirq.c:1043
 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>