rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=9b34/1/0x4000000000000000 softirq=17961/18011 fqs=4
rcu: 	(detected by 0, t=10506 jiffies, g=10393, q=1401 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6126 Comm: syz.3.20 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__lock_acquire+0x1b3/0x1ce0 kernel/locking/lockdep.c:5174
Code: 00 49 89 44 24 08 41 8b b5 d4 0a 00 00 31 c0 65 8b 15 69 19 3f 12 85 f6 0f 95 c0 85 d2 0f 95 c2 41 c1 e6 0f c1 e1 10 0f b6 d2 <45> 0f b7 f6 41 c1 e0 13 8d 04 50 8b 14 24 81 e1 00 00 03 00 c1 e0
RSP: 0018:ffffc90000a08bf0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888028810af0 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff888028810b40
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000050 R11: 0000000000000001 R12: ffff888028810b40
R13: ffff888028810000 R14: 0000000000000000 R15: ffffffff9b0843d0
FS:  00007fd90f34b6c0(0000) GS:ffff8881247b8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555f3d05c8 CR3: 000000005b631000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 lock_acquire kernel/locking/lockdep.c:5868 [inline]
 lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5825
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x135/0x3a0 lib/debugobjects.c:873
 debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline]
 debug_deactivate kernel/time/hrtimer.c:490 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1729 [inline]
 __hrtimer_run_queues+0x46f/0xad0 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lockdep_unregister_key+0xe9/0x140 kernel/locking/lockdep.c:6616
Code: 48 89 ef e8 b9 e5 ff ff 48 83 2d 89 e1 5e 14 01 89 c3 e8 da ee ff ff 9c 58 f6 c4 02 75 52 41 f7 c4 00 02 00 00 74 01 fb 84 db <75> 1b 5b 5d 41 5c e9 4c 76 0a 00 8b 05 4a 1c 14 0f 31 db 85 c0 74
RSP: 0018:ffffc90003a67318 EFLAGS: 00000246
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8df440ae RDI: ffffffff8c162a00
RBP: ffffffff975b4a38 R08: 000000000000be39 R09: ffffffff95f7c652
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000246
R13: ffff88807dab8000 R14: ffff888029bb8000 R15: ffff88807dab8000
 __qdisc_destroy+0x11a/0x4d0 net/sched/sch_generic.c:1083
 qdisc_put+0xab/0xe0 net/sched/sch_generic.c:1109
 taprio_attach+0x1fc/0x370 net/sched/sch_taprio.c:2160
 qdisc_graft+0xe3c/0x17c0 net/sched/sch_api.c:1162
 __tc_modify_qdisc net/sched/sch_api.c:1756 [inline]
 tc_modify_qdisc+0xf5c/0x2170 net/sched/sch_api.c:1812
 rtnetlink_rcv_msg+0x3c6/0xe90 net/core/rtnetlink.c:6955
 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 ____sys_sendmsg+0xa98/0xc70 net/socket.c:2614
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
 __sys_sendmsg+0x16d/0x220 net/socket.c:2700
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd90e58ebe9
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:00007fd90f34b038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fd90e7c5fa0 RCX: 00007fd90e58ebe9
RDX: 0000000000000000 RSI: 00002000000007c0 RDI: 0000000000000004
RBP: 00007fd90e611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd90e7c6038 R14: 00007fd90e7c5fa0 R15: 00007ffe392571d8
 </TASK>
rcu: rcu_preempt kthread starved for 10488 jiffies! g10393 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:27672 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d4/0x6f0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 5978 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xdfd/0x1600 kernel/smp.c:877
Code: 57 48 8b 54 24 10 4c 89 74 24 10 49 89 d5 48 89 d5 48 89 54 24 18 49 c1 ed 03 83 e5 07 4d 01 e5 83 c5 03 e8 b5 ff 0b 00 f3 90 <41> 0f b6 45 00 40 38 c5 7c 08 84 c0 0f 85 e0 05 00 00 8b 43 08 31
RSP: 0000:ffffc90003d1f8a8 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b853fe80 RCX: ffffffff81af8ea1
RDX: ffff88802e214880 RSI: ffffffff81af8e7b RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffed10170a7fd1 R14: 0000000000000001 R15: 0000000000000001
FS:  0000555567108500(0000) GS:ffff8881246b8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555671235c8 CR3: 000000007bb08000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1044
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x4a0/0x17a0 arch/x86/mm/tlb.c:1451
 flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline]
 ptep_clear_flush+0x136/0x180 mm/pgtable-generic.c:101
 wp_page_copy mm/memory.c:3618 [inline]
 do_wp_page+0x1683/0x4f00 mm/memory.c:4013
 handle_pte_fault mm/memory.c:6068 [inline]
 __handle_mm_fault+0x1b2d/0x2a50 mm/memory.c:6195
 handle_mm_fault+0x589/0xd10 mm/memory.c:6364
 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7fce4434d03f
Code: 8d 34 19 48 39 d5 48 89 75 60 0f 95 c2 48 29 d8 48 83 c1 10 0f b6 d2 48 83 c8 01 48 c1 e2 02 48 09 da 48 83 ca 01 48 89 51 f8 <48> 89 46 08 eb 80 48 8d 0d 21 e9 0e 00 48 8d 15 25 fb 0e 00 bf 01
RSP: 002b:00007ffd63fc65e0 EFLAGS: 00010206
RAX: 0000000000006a41 RBX: 0000000000008040 RCX: 000055556711b590
RDX: 0000000000008041 RSI: 00005555671235c0 RDI: 0000000000000004
RBP: 00007fce44597cc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000802 R12: 0000000000008030
R13: 0000000000000076 R14: 00007fce44597d20 R15: 0000000000000000
 </TASK>