rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10500 ticks this GP) idle=1d1/1/0x4000000000000000 softirq=7597/7597 fqs=7 
	(t=10502 jiffies g=8365 q=537)
rcu: rcu_preempt kthread starved for 10489 jiffies! g8365 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: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
CPU: 0 PID: 4418 Comm: syz.3.20 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:memcpy_erms+0x6/0x10 arch/x86/lib/memcpy_64.S:55
Code: fe ff ff 00 eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 90 90 90 90 90 90 48 89 f8 48 89 d1 <f3> a4 c3 90 90 90 90 90 90 90 48 89 f8 48 83 fa 20 72 7e 40 38 fe
RSP: 0018:ffffc9000393fb18 EFLAGS: 00000002
RAX: ffffc9000393fe00 RBX: 0000000000000021 RCX: 0000000000000030
RDX: 0000000000000030 RSI: ffff88802a229168 RDI: ffffc9000393fe00
RBP: ffff88802a229150 R08: dffffc0000000000 R09: fffff52000727fc6
R10: fffff52000727fc6 R11: 1ffff92000727fc0 R12: ffffc9000393fe00
R13: 1ffff110037035c1 R14: dffffc0000000000 R15: ffff88801b81adf8
FS:  000055557bf06500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000007087c000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 copy_siginfo include/linux/signal.h:17 [inline]
 collect_signal kernel/signal.c:590 [inline]
 __dequeue_signal+0x356/0x5d0 kernel/signal.c:619
 dequeue_signal+0xa2/0x440 kernel/signal.c:639
 get_signal+0x6fe/0x12c0 kernel/signal.c:2781
 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: 0033:0x7f055eed1973
Code: 0f 1f 80 00 00 00 00 8b 78 24 45 31 c0 83 ff 3f 7f 18 be 01 00 00 00 89 f9 45 31 c0 48 d3 e6 48 23 35 49 3d e9 00 41 0f 95 c0 <48> 8d b0 98 00 00 00 44 89 c9 e9 4e f5 ff ff 66 0f 1f 44 00 00 ba
RSP: 002b:00007ffe658bbbb8 EFLAGS: 00000246
RAX: 00007f055f235fa0 RBX: 00007f055f235fa8 RCX: 0000000000000005
RDX: 0000000000003c03 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f055f235fb0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 00007f055f235fa0
R13: 0000200000000000 R14: 00007ffe658bbbc8 R15: 0000000000000004
 </TASK>
NMI backtrace for cpu 1
CPU: 1 PID: 4416 Comm: syz.4.24 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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: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 8e 1d aa f7 48 89 df e8 56 f2 aa f7 e8 d1 8c cb f7 fb bf 01 00 00 00 <e8> a6 15 9f f7 65 8b 05 a7 13 50 76 85 c0 74 02 5b c3 e8 54 1e 4e
RSP: 0018:ffffc9000390fbc0 EFLAGS: 00000282
RAX: f6d0bffa15ece100 RBX: ffff888029f7ca00 RCX: f6d0bffa15ece100
RDX: dffffc0000000000 RSI: ffffffff8a0b1620 RDI: 0000000000000001
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed10053ef941
R10: ffffed10053ef941 R11: 1ffff110053ef940 R12: ffff888029f7ca00
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: 0033:0x7f3400bc1750
Code: 00 eb 98 48 8b 54 24 08 48 8d 35 ed fe 1b 00 48 8d 3d f0 fe 1b 00 31 c0 e8 fd c8 ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 <53> 48 8b 1d 48 56 37 00 45 31 d2 31 c9 48 8b 17 45 31 db 4c 8d 83
RSP: 002b:00007fff6e576d58 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f3400f34fa8 RCX: 00007f3400cfdbe9
RDX: ffffffffffffffff RSI: 0000000000000081 RDI: 00007f3400f34fb0
RBP: 00007f3400f34fb0 R08: 0027d73865a7d3d4 R09: 000000066e57709f
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3400f34fa0
R13: 0000200000000000 R14: 00007fff6e576d68 R15: 0000000000000004
 </TASK>
sched: RT throttling activated