rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10501 ticks this GP) idle=d19/1/0x4000000000000000 softirq=7892/7892 fqs=0 
	(t=10502 jiffies g=8049 q=181)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g8049 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=2475
rcu: rcu_preempt kthread starved for 10505 jiffies! g8049 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:28064 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 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 1
CPU: 1 PID: 4737 Comm: syz.0.94 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 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+0x6d8/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 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+0x4fe/0xc40 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:fpu__restore_sig+0x64/0xf50 arch/x86/kernel/fpu/signal.c:431
Code: 44 24 60 b3 8a b5 41 48 c7 44 24 68 07 ab a7 8b 48 c7 44 24 70 20 cc 2b 81 4c 8d 74 24 60 49 c1 ee 03 43 c7 04 3e f1 f1 f1 f1 <48> b8 04 f2 f2 f2 f2 00 00 00 4b 89 44 3e 11 43 c7 44 3e 1c f3 f3
RSP: 0018:ffffc90003137b40 EFLAGS: 00000a06
RAX: d1b1bddafd01f000 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffffc90003137fd0 RSI: 0000000000000000 RDI: 00007fd15dcb5d00
RBP: ffffc90003137cf0 R08: dffffc0000000000 R09: fffff52000626fc4
R10: 0000000000000000 R11: 0000000000000010 R12: 00007fd15dcb5d00
R13: 1ffff92000626fff R14: 1ffff92000626f74 R15: dffffc0000000000
 restore_sigcontext arch/x86/kernel/signal.c:139 [inline]
 __ia32_sys_rt_sigreturn+0x649/0x790 arch/x86/kernel/signal.c:674
 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: 0033:0x7fd15fa70749
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:00007fd15dcb60e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007fd15fcc7098 RCX: 00007fd15fa70749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd15fcc7098
RBP: 00007fd15fcc7090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd15fcc7128 R14: 00007ffc60a6a390 R15: 00007ffc60a6a478
 </TASK>
NMI backtrace for cpu 1
CPU: 1 PID: 4737 Comm: syz.0.94 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 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+0x6d8/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 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+0x4fe/0xc40 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:fpu__restore_sig+0x64/0xf50 arch/x86/kernel/fpu/signal.c:431
Code: 44 24 60 b3 8a b5 41 48 c7 44 24 68 07 ab a7 8b 48 c7 44 24 70 20 cc 2b 81 4c 8d 74 24 60 49 c1 ee 03 43 c7 04 3e f1 f1 f1 f1 <48> b8 04 f2 f2 f2 f2 00 00 00 4b 89 44 3e 11 43 c7 44 3e 1c f3 f3
RSP: 0018:ffffc90003137b40 EFLAGS: 00000a06
RAX: d1b1bddafd01f000 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffffc90003137fd0 RSI: 0000000000000000 RDI: 00007fd15dcb5d00
RBP: ffffc90003137cf0 R08: dffffc0000000000 R09: fffff52000626fc4
R10: 0000000000000000 R11: 0000000000000010 R12: 00007fd15dcb5d00
R13: 1ffff92000626fff R14: 1ffff92000626f74 R15: dffffc0000000000
 restore_sigcontext arch/x86/kernel/signal.c:139 [inline]
 __ia32_sys_rt_sigreturn+0x649/0x790 arch/x86/kernel/signal.c:674
 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: 0033:0x7fd15fa70749
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:00007fd15dcb60e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007fd15fcc7098 RCX: 00007fd15fa70749
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fd15fcc7098
RBP: 00007fd15fcc7090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd15fcc7128 R14: 00007ffc60a6a390 R15: 00007ffc60a6a478
 </TASK>
sched: RT throttling activated