rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 GPs behind) idle=08f/1/0x4000000000000000 softirq=18028/18029 fqs=526 
	(t=10500 jiffies g=22697 q=74)
rcu: rcu_preempt kthread starved for 9447 jiffies! g22697 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:27848 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:722
NMI backtrace for cpu 0
CPU: 0 PID: 7098 Comm: syz.1.687 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:3932 [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:1690 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 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:constant_test_bit arch/x86/include/asm/bitops.h:207 [inline]
RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:135 [inline]
RIP: 0010:test_ti_thread_flag include/linux/thread_info.h:118 [inline]
RIP: 0010:restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:-1 [inline]
RIP: 0010:__fpu_restore_sig arch/x86/kernel/fpu/signal.c:334 [inline]
RIP: 0010:fpu__restore_sig+0x524/0xf50 arch/x86/kernel/fpu/signal.c:466
Code: 00 00 41 ff 8e 88 17 00 00 31 ff 44 89 e6 e8 63 f6 4b 00 4c 89 f7 be 08 00 00 00 e8 96 6c 91 00 48 8b 44 24 48 42 80 3c 38 00 <74> 08 4c 89 f7 e8 f2 6a 91 00 4d 8b 36 41 81 e6 00 40 00 00 31 ff
RSP: 0018:ffffc90003d9fb40 EFLAGS: 00000246
RAX: 1ffff11003ab93b8 RBX: 1ffff11003ab96a9 RCX: ffffffff812bcf2a
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88801d5c9dc0
RBP: ffffc90003d9fcf0 R08: dffffc0000000000 R09: ffffed1003ab93b9
R10: ffffed1003ab93b9 R11: 1ffff11003ab93b8 R12: 0000000000000000
R13: 0000000000000000 R14: ffff88801d5c9dc0 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: 0033:0x7f5c1229349c
Code: e8 f9 89 ff ff 49 39 ec 0f 84 04 fd ff ff 49 8b 0c 24 49 8b 54 24 f8 49 8d 44 24 f8 48 39 d1 73 5f 0f 1f 44 00 00 48 89 50 08 <48> 89 c6 48 8b 50 f8 48 83 e8 08 48 39 d1 72 ec 49 83 c4 08 48 89
RSP: 002b:00007fff08336150 EFLAGS: 00000293
RAX: 00007f5c11a25650 RBX: 00007f5c13109720 RCX: ffffffff81d55720
RDX: ffffffff81d558be RSI: 00007f5c11a25658 RDI: 00007f5c11a23010
RBP: 00007f5c11a2a488 R08: 00007f5c11a230c8 R09: 00007f5c125c6000
R10: 00007f5c11a23008 R11: 0000000000000007 R12: 00007f5c11a25670
R13: 00007f5c125da038 R14: 00007fff08336218 R15: 00007f5c11a23008
 </TASK>