rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=43d/1/0x4000000000000000 softirq=5555/5555 fqs=0 
	(t=10500 jiffies g=4261 q=84)
rcu: rcu_preempt kthread starved for 10500 jiffies! g4261 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: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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4192 Comm: syz-executor162 Not tainted 5.15.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:174 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x2c/0x60 kernel/kcov.c:206
Code: 04 24 65 48 8b 0d a4 b1 8a 7e 65 8b 15 a5 b1 8a 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c <8b> 91 10 16 00 00 83 fa 02 75 21 48 8b 91 18 16 00 00 48 8b 32 48
RSP: 0018:ffffc90002f5fa68 EFLAGS: 00000046
RAX: ffffffff817de0b3 RBX: 0000000000000000 RCX: ffff888027695940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff81485d6b
RBP: ffffc90002f5fb30 R08: dffffc0000000000 R09: ffffed1004ed2b29
R10: ffffed1004ed2b29 R11: 1ffff11004ed2b28 R12: ffffffff812bda35
R13: 0000000000000000 R14: ffffffff81485d6b R15: 1ffff920005ebf54
FS:  00005555804073c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc8742d7320 CR3: 00000000752ec000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 trace_irq_disable_rcuidle+0x13/0x180 include/trace/events/preemptirq.h:36
 __local_bh_enable_ip+0xcb/0x1b0 kernel/softirq.c:365
 fpregs_unlock arch/x86/include/asm/fpu/api.h:78 [inline]
 restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:300 [inline]
 __fpu_restore_sig arch/x86/kernel/fpu/signal.c:334 [inline]
 fpu__restore_sig+0x785/0xf50 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: 0033:0x7fc8742bdba9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 1f 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffed17bf138 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fc8742bdba9
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc87430e191
R13: 00007ffed17bf460 R14: 00007ffed17bf170 R15: 0000000000000000
 </TASK>
NMI backtrace for cpu 1
CPU: 1 PID: 4191 Comm: syz-executor162 Not tainted 5.15.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: f6 ff 0f 1f 00 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 4e d6 b1 f7 48 89 df e8 16 ab b2 f7 e8 71 4f d3 f7 fb bf 01 00 00 00 <e8> 46 cf a6 f7 65 8b 05 e7 e2 57 76 85 c0 74 02 5b c3 e8 94 ed 55
RSP: 0018:ffffc90002ecfbc0 EFLAGS: 00000282
RAX: 9202705682eb1400 RBX: ffff88802a5a8940 RCX: 9202705682eb1400
RDX: dffffc0000000000 RSI: ffffffff8a0b0fc0 RDI: 0000000000000001
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed10054b5129
R10: ffffed10054b5129 R11: 1ffff110054b5128 R12: ffff88802a5a8940
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
 spin_unlock_irq include/linux/spinlock.h:413 [inline]
 get_signal+0x11d6/0x12c0 kernel/signal.c:2903
 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc87430d5e8
Code: 0d c5 3b 03 00 39 48 08 75 ac 48 8b 15 b1 3b 03 00 48 8b 38 48 89 10 c7 05 d9 3b 03 00 00 00 00 00 e8 fc 20 f9 ff eb 8e 00 00 <48> 83 ec 08 48 83 c4 08 c3 00 00 00 00 00 00 00 00 00 00 00 00 00
RSP: 002b:00007ffed17bf0d8 EFLAGS: 00010202
RAX: 00007fc874341ad0 RBX: 0000000000000000 RCX: 0000000000000004
RDX: 00007fc874343e40 RSI: 0000000000000000 RDI: 00007fc874341ad0
RBP: 00007fc874340130 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00007fc874343e28
R13: 0000000000000000 R14: 00007fc874343e40 R15: 00007fc874280840
 </TASK>