rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10500 ticks this GP) idle=aa9/1/0x4000000000000000 softirq=31767/31767 fqs=0 
	(t=10500 jiffies g=48001 q=197)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g48001 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=40387
rcu: rcu_preempt kthread starved for 10500 jiffies! g48001 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:27632 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 11528 Comm: syz.5.1830 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_cpu_stall+0x318/0x5f0 kernel/rcu/tree_stall.h:631
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6ea/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:cake_heapify+0x27f/0x6a0 net/sched/sch_cake.c:1503
Code: 10 84 c0 0f 85 5d 03 00 00 45 8b 36 44 89 f7 44 89 e6 e8 b4 be 64 f9 45 39 e6 44 0f 47 eb 45 0f 47 e6 45 89 ee 44 89 64 24 0c <44> 0f b7 fd 44 89 f7 44 89 fe e8 92 be 64 f9 45 39 fe 0f 84 7c 03
RSP: 0018:ffffc9000325e620 EFLAGS: 00000246
RAX: ffffffff881463bc RBX: 0000000000000d7e RCX: ffff8880750c3b80
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000000006be R08: ffffffff901d418f R09: 1ffffffff203a831
R10: dffffc0000000000 R11: fffffbfff203a832 R12: 0000000000000000
R13: 00000000000006be R14: 00000000000006be R15: ffff8880715e82d0
 cake_drop net/sched/sch_cake.c:1575 [inline]
 cake_enqueue+0x33d9/0x7fc0 net/sched/sch_cake.c:1949
 qdisc_enqueue include/net/sch_generic.h:832 [inline]
 sfb_enqueue+0xa05/0x1750 net/sched/sch_sfb.c:405
 dev_qdisc_enqueue+0x48/0x210 net/core/dev.c:3865
 __dev_xmit_skb net/core/dev.c:3949 [inline]
 __dev_queue_xmit+0xc25/0x2f80 net/core/dev.c:4266
 tipc_l2_send_msg+0x30a/0x3c0 net/tipc/bearer.c:518
 tipc_bearer_xmit_skb+0x292/0x3c0 net/tipc/bearer.c:577
 tipc_enable_bearer net/tipc/bearer.c:368 [inline]
 __tipc_nl_bearer_enable+0xfba/0x12c0 net/tipc/bearer.c:1049
 __tipc_nl_compat_doit net/tipc/netlink_compat.c:375 [inline]
 tipc_nl_compat_doit+0x3d9/0x610 net/tipc/netlink_compat.c:397
 tipc_nl_compat_handle net/tipc/netlink_compat.c:-1 [inline]
 tipc_nl_compat_recv+0x536/0xaf0 net/tipc/netlink_compat.c:1325
 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
 genl_rcv_msg+0xcea/0xf90 net/netlink/genetlink.c:792
 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
 __sys_sendmsg net/socket.c:2528 [inline]
 __do_sys_sendmsg net/socket.c:2537 [inline]
 __se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9b3dd1e799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9b3bf78028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9b3df97fa0 RCX: 00007f9b3dd1e799
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000006
RBP: 00007f9b3ddb4c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9b3df98038 R14: 00007f9b3df97fa0 R15: 00007ffda47ae508
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 11528 Comm: syz.5.1830 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6ea/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:cake_heapify+0x27f/0x6a0 net/sched/sch_cake.c:1503
Code: 10 84 c0 0f 85 5d 03 00 00 45 8b 36 44 89 f7 44 89 e6 e8 b4 be 64 f9 45 39 e6 44 0f 47 eb 45 0f 47 e6 45 89 ee 44 89 64 24 0c <44> 0f b7 fd 44 89 f7 44 89 fe e8 92 be 64 f9 45 39 fe 0f 84 7c 03
RSP: 0018:ffffc9000325e620 EFLAGS: 00000246
RAX: ffffffff881463bc RBX: 0000000000000d7e RCX: ffff8880750c3b80
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00000000000006be R08: ffffffff901d418f R09: 1ffffffff203a831
R10: dffffc0000000000 R11: fffffbfff203a832 R12: 0000000000000000
R13: 00000000000006be R14: 00000000000006be R15: ffff8880715e82d0
 cake_drop net/sched/sch_cake.c:1575 [inline]
 cake_enqueue+0x33d9/0x7fc0 net/sched/sch_cake.c:1949
 qdisc_enqueue include/net/sch_generic.h:832 [inline]
 sfb_enqueue+0xa05/0x1750 net/sched/sch_sfb.c:405
 dev_qdisc_enqueue+0x48/0x210 net/core/dev.c:3865
 __dev_xmit_skb net/core/dev.c:3949 [inline]
 __dev_queue_xmit+0xc25/0x2f80 net/core/dev.c:4266
 tipc_l2_send_msg+0x30a/0x3c0 net/tipc/bearer.c:518
 tipc_bearer_xmit_skb+0x292/0x3c0 net/tipc/bearer.c:577
 tipc_enable_bearer net/tipc/bearer.c:368 [inline]
 __tipc_nl_bearer_enable+0xfba/0x12c0 net/tipc/bearer.c:1049
 __tipc_nl_compat_doit net/tipc/netlink_compat.c:375 [inline]
 tipc_nl_compat_doit+0x3d9/0x610 net/tipc/netlink_compat.c:397
 tipc_nl_compat_handle net/tipc/netlink_compat.c:-1 [inline]
 tipc_nl_compat_recv+0x536/0xaf0 net/tipc/netlink_compat.c:1325
 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:775 [inline]
 genl_rcv_msg+0xcea/0xf90 net/netlink/genetlink.c:792
 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2507
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:803
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x774/0x920 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x8ba/0xbe0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2445
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2499
 __sys_sendmsg net/socket.c:2528 [inline]
 __do_sys_sendmsg net/socket.c:2537 [inline]
 __se_sys_sendmsg+0x1af/0x290 net/socket.c:2535
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9b3dd1e799
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9b3bf78028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f9b3df97fa0 RCX: 00007f9b3dd1e799
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000000000000006
RBP: 00007f9b3ddb4c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9b3df98038 R14: 00007f9b3df97fa0 R15: 00007ffda47ae508
 </TASK>