rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=447/1/0x4000000000000000 softirq=7583/7583 fqs=7 
	(t=10501 jiffies g=9229 q=267)
rcu: rcu_preempt kthread starved for 10487 jiffies! g9229 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:28112 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11c3/0x4350 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11f0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
 kthread+0x42e/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: 4428 Comm: syz.2.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:_raw_spin_lock_irqsave+0x6/0x100 kernel/locking/spinlock.c:161
Code: 00 00 45 31 c9 ff 74 24 08 e8 a6 52 94 f7 48 83 c4 08 48 89 df 5b e9 e9 a5 95 f7 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 <41> 56 41 54 53 48 83 e4 e0 48 83 ec 60 48 89 fb 65 48 8b 04 25 28
RSP: 0018:ffffc90003f6f9f0 EFLAGS: 00000002
RAX: 000ffff8880790ca RBX: ffff8880790ca0b0 RCX: 0000000000009a20
RDX: 0000000000000000 RSI: ffffffff8a2cbea0 RDI: ffffffff964f0268
RBP: ffffc90003f6f9f8 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff520007edf30 R12: ffffffff964f0260
R13: ffff8880790ca0e0 R14: ffffffff8a2cbea0 R15: dffffc0000000000
FS:  0000555560f64500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 0000000058d61000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 debug_object_activate+0x63/0x4e0 lib/debugobjects.c:694
 debug_hrtimer_activate kernel/time/hrtimer.c:410 [inline]
 debug_activate kernel/time/hrtimer.c:465 [inline]
 enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1069
 __hrtimer_start_range_ns kernel/time/hrtimer.c:1244 [inline]
 hrtimer_start_range_ns+0xaba/0xc40 kernel/time/hrtimer.c:1286
 posixtimer_rearm+0x12a/0x340 kernel/time/posix-timers.c:329
 dequeue_signal+0x174/0x440 kernel/signal.c:696
 get_signal+0x823/0x12e0 kernel/signal.c:2782
 arch_do_signal_or_restart+0xe6/0x12a0 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+0xee/0x180 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: 0033:0x7f70c84e6e50
Code: f2 72 8c e9 0e ff ff ff 66 90 4c 89 e6 48 89 df e8 15 bb fe ff 48 8b 43 40 44 01 63 30 4c 29 e0 83 e5 02 48 89 43 40 c6 00 00 <0f> 84 ea fd ff ff 48 8b 43 40 c6 40 01 00 49 83 fc 03 0f 85 d8 fd
RSP: 002b:00007ffeb37bc630 EFLAGS: 00000202
RAX: 0000001b31363fc0 RBX: 00007f70c93cc720 RCX: 0000000000000000
RDX: 0000001b3132422c RSI: 0000000000000003 RDI: 00007f70c93cc720
RBP: 0000000000000002 R08: 0000000000000000 R09: 00007f70c889d038
R10: 0000000000000003 R11: 0000000000000004 R12: 0000000000000003
R13: 000000000000003c R14: 0000000000000000 R15: 0000000000000004
 </TASK>
NMI backtrace for cpu 1
CPU: 1 PID: 4427 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 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+0x22d/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31f/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+0x6ec/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 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+0x4b0/0xb60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x397/0x8b0 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:lock_acquire+0x208/0x400 kernel/locking/lockdep.c:5627
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3d 04 f8 0f 85 f1 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 43 c7 44 3d 08 00 00 00 00 65 48 8b 04
RSP: 0018:ffffc90003f2fa60 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 02a914c920737300
RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a2a40
RBP: ffffc90003f2fb80 R08: dffffc0000000000 R09: 1ffffffff203d21e
R10: dffffc0000000000 R11: fffffbfff203d21f R12: ffff88801f2d6a28
R13: 1ffff920007e5f58 R14: 0000000000000246 R15: dffffc0000000000
 __might_fault+0xb3/0x110 mm/memory.c:5357
 _copy_from_user+0x29/0x170 lib/usercopy.c:14
 copy_from_user include/linux/uaccess.h:192 [inline]
 restore_altstack+0xa8/0x380 kernel/signal.c:4253
 __ia32_sys_rt_sigreturn+0x624/0x750 arch/x86/kernel/signal.c:677
 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: 0033:0x7f2519f9ab37
Code: 83 c4 08 c3 0f 1f 80 00 00 00 00 48 83 ec 08 48 89 f2 48 63 ff 4c 89 d6 41 51 31 c0 4d 89 c1 49 89 c8 4c 89 d9 e8 09 63 14 00 <5a> 59 48 83 c4 08 c3 66 90 66 0f ef c0 4c 63 c9 49 89 d0 0f 11 07
RSP: 002b:00007ffc46cbb4c0 EFLAGS: 00000217
RAX: 0000000000000000 RBX: 00007f251a368fa0 RCX: 00007f251a0e0e59
RDX: 0000200000000040 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 00007f251a176e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f251a368fac R14: 00007f251a368fa0 R15: 00007f251a368fa0
 </TASK>
sched: RT throttling activated