rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=46f/1/0x4000000000000000 softirq=7197/7199 fqs=121 
	(t=10500 jiffies g=6457 q=326)
rcu: rcu_preempt kthread starved for 10258 jiffies! g6457 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:27008 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:729
NMI backtrace for cpu 1
CPU: 1 PID: 4719 Comm: syz.4.107 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:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202
Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d d0 6b f1 0b 48 89 de 5b e9 d7 9e 43 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d a4 a3 8a 7e 65 8b 15 a5 a3 8a 7e 81 e2 00
RSP: 0018:ffffc9000306fb30 EFLAGS: 00000a02
RAX: 1ffffffff177806e RBX: 1ffff1100ce7be19 RCX: ffff8880673dd940
RDX: 0000000000000000 RSI: 0000000046505853 RDI: 0000000000000000
RBP: ffffc9000306fcf0 R08: 0000000000000000 R09: fffff5200060df90
R10: fffff5200060df90 R11: 1ffff9200060df8a R12: 00007fff3c2d1f40
R13: 00000000000002f8 R14: ffff8880673dd940 R15: dffffc0000000000
 local_bh_disable+0x5/0x20 include/linux/bottom_half.h:18
 fpregs_lock arch/x86/include/asm/fpu/api.h:70 [inline]
 restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:257 [inline]
 __fpu_restore_sig arch/x86/kernel/fpu/signal.c:334 [inline]
 fpu__restore_sig+0x45d/0xf50 arch/x86/kernel/fpu/signal.c:466
 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: 0033:0x7f5d17560fbb
Code: 03 14 ca 80 3d 0d 8e 37 00 00 49 89 d6 48 89 d5 74 28 25 ff 0f 00 00 83 f0 3d 8d 04 c0 89 c5 c1 ed 04 31 c5 69 ed 2d eb d4 27 <89> e8 c1 e8 0f 31 c5 81 e5 ff 0f 00 00 48 31 d5 80 3d 76 30 37 00
RSP: 002b:00007fff3c2d2320 EFLAGS: 00000a07
RAX: 00000000000023dc RBX: 00007f5d18407720 RCX: 0000000000000734
RDX: ffffffff83d9e3c1 RSI: ffffffff83d9e4aa RDI: 0000000000000002
RBP: 0000000074737f8d R08: 00007f5d178d8038 R09: 00007f5d178c4000
R10: 00007f5d170f1008 R11: 0000000000000002 R12: 0000000000000002
R13: 0000000000000000 R14: ffffffff83d9e3c1 R15: 0000000000000734
 </TASK>