rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (2 ticks this GP) idle=e284/1/0x4000000000000000 softirq=19030/19030 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=14741, q=308 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 7211 Comm: syz.2.375 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3801 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3821 [inline]
RIP: 0010:validate_chain+0xaa/0x2140 kernel/locking/lockdep.c:3876
Code: 0c 87 e5 ff 90 0f 0b 90 90 90 48 bb eb 83 b5 80 46 86 c8 61 49 0f af df 48 c1 eb 2d 48 8b 04 dd 60 23 32 93 48 85 c0 0f 94 c1 <48> 83 c0 f8 0f 94 c2 08 ca 0f 84 24 01 00 00 e8 e2 9b ff ff 83 3d
RSP: 0018:ffffc90000007a58 EFLAGS: 00000086
RAX: ffffffff93763eb8 RBX: 000000000007c792 RCX: 0000000000040000
RDX: 0000000000000001 RSI: ffff8880261ca998 RDI: ffff8880261c9e40
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81ada912
R10: dffffc0000000000 R11: fffffbfff1ef9e8f R12: 0000000000000001
R13: ffff8880261ca970 R14: ffff8880261ca998 R15: 4d4df099ab2b819a
FS:  00007fd5719a46c0(0000) GS:ffff888126139000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558d2cf808 CR3: 0000000028b48000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
 _raw_spin_lock_irq+0xa2/0xf0 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1781 [inline]
 __hrtimer_run_queues+0x602/0xc60 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:preempt_schedule_irq+0xb0/0x150 kernel/sched/core.c:7256
Code: 24 20 f6 44 24 21 02 74 0c 90 0f 0b 48 f7 03 10 00 00 00 74 64 bf 01 00 00 00 e8 5b 33 48 f6 e8 b6 06 80 f6 fb bf 01 00 00 00 <e8> 5b ab ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0018:ffffc9000c506f40 EFLAGS: 00000286
RAX: 0b6e82737ecd1400 RBX: 0000000000000000 RCX: 0b6e82737ecd1400
RDX: 0000000000000006 RSI: ffffffff8d70edc4 RDI: 0000000000000001
RBP: ffffc9000c506fe0 R08: ffffffff8f7cf477 R09: 1ffffffff1ef9e8e
R10: dffffc0000000000 R11: fffffbfff1ef9e8f R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff920018a0de8
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lockdep_unregister_key+0x2c5/0x310 kernel/locking/lockdep.c:6616
Code: 65 48 8b 05 2d f9 d0 10 48 3b 44 24 10 0f 84 26 fe ff ff e8 dd 19 a9 09 e8 08 1b a9 09 41 f7 c7 00 02 00 00 74 bd fb 40 84 ed <75> bc eb cd 90 0f 0b 90 e9 19 ff ff ff 90 0f 0b 90 e9 2a ff ff ff
RSP: 0018:ffffc9000c5070a8 EFLAGS: 00000246
RAX: 0b6e82737ecd1400 RBX: ffff88802795d298 RCX: 0b6e82737ecd1400
RDX: ffffffff93322358 RSI: ffffffff8d7230ed RDI: ffffffff8bbf08e0
RBP: ffff88802795d200 R08: 0000000000000000 R09: ffffffff81aa74d8
R10: dffffc0000000000 R11: fffffbfff1ef9e8f R12: 0000000000000000
R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000000a06
 __qdisc_destroy+0x166/0x420 net/sched/sch_generic.c:1086
 taprio_attach+0x25a/0x380 net/sched/sch_taprio.c:2160
 qdisc_graft+0x1175/0x1590 net/sched/sch_api.c:1162
 __tc_modify_qdisc net/sched/sch_api.c:1761 [inline]
 tc_modify_qdisc+0x16d3/0x2020 net/sched/sch_api.c:1817
 rtnetlink_rcv_msg+0x77c/0xb70 net/core/rtnetlink.c:6960
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x505/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmsg net/socket.c:2716 [inline]
 __do_sys_sendmsg net/socket.c:2721 [inline]
 __se_sys_sendmsg net/socket.c:2719 [inline]
 __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2719
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd570b8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd5719a4038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd570de5fa0 RCX: 00007fd570b8f749
RDX: 0000000000048004 RSI: 00002000000007c0 RDI: 0000000000000004
RBP: 00007fd570c13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd570de6038 R14: 00007fd570de5fa0 R15: 00007fff6e370718
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g14741 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=8938
rcu: rcu_preempt kthread starved for 10502 jiffies! g14741 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:27224 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>