rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10500 ticks this GP) idle=d6f/1/0x4000000000000000 softirq=7157/7157 fqs=0 
	(t=10502 jiffies g=8009 q=306)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g8009 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=4881
rcu: rcu_preempt kthread starved for 10505 jiffies! g8009 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28032 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
CPU: 1 PID: 4512 Comm: syz.0.57 Not tainted 5.15.186-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:filter_irq_stacks+0x2e/0x90 kernel/stacktrace.c:398
Code: 41 55 41 54 53 85 f6 74 70 49 89 fe 41 89 f4 31 db 49 bd 00 00 00 00 00 fc ff df 49 89 ff 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 ff e8 08 cc 56 00 49 8b 04 de 48 3d e0 01 c0 89 0f 93
RSP: 0018:ffffc900035af7c0 EFLAGS: 00000046
RAX: 1ffff920006b5f03 RBX: 0000000000000005 RCX: 1fc96082cf81a201
RDX: 0000000000000001 RSI: 000000000000000e RDI: ffffc900035af7f0
RBP: ffffc900035afa18 R08: dffffc0000000000 R09: fffffbfff1ad2f76
R10: fffffbfff1ad2f76 R11: 1ffffffff1ad2f75 R12: 000000000000000e
R13: dffffc0000000000 R14: ffffc900035af7f0 R15: ffffc900035af818
FS:  00007efff70896c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555571e045c8 CR3: 000000001e721000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 kasan_save_stack mm/kasan/common.c:39 [inline]
 kasan_set_track+0x55/0x70 mm/kasan/common.c:46
 kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
 ____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1705 [inline]
 slab_free_freelist_hook+0xea/0x170 mm/slub.c:1731
 slab_free mm/slub.c:3499 [inline]
 kmem_cache_free+0x8f/0x210 mm/slub.c:3515
 __sigqueue_free kernel/signal.c:458 [inline]
 collect_signal kernel/signal.c:597 [inline]
 __dequeue_signal+0x4c4/0x5d0 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: 0033:0x7efff9221929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007efff70890e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007efff9448fa8 RCX: 00007efff9221929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007efff9448fa8
RBP: 00007efff9448fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007efff9448fac
R13: 0000000000000000 R14: 00007ffea43802d0 R15: 00007ffea43803b8
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 4519 Comm: syz.0.57 Not tainted 5.15.186-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:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627
Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 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 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b
RSP: 0018:ffffc900034cf9e0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: cb2910935f038400
RDX: 0000000000000000 RSI: ffffffff8a0b2460 RDI: ffffffff8a59ab80
RBP: ffffc900034cfaf8 R08: dffffc0000000000 R09: fffffbfff1ff741f
R10: fffffbfff1ff741f R11: 1ffffffff1ff741e R12: ffff888075203928
R13: 1ffff92000699f48 R14: 0000000000000246 R15: dffffc0000000000
 __might_fault+0xb3/0x110 mm/memory.c:5357
 __copy_from_user include/linux/uaccess.h:109 [inline]
 check_xstate_in_sigframe arch/x86/kernel/fpu/signal.c:33 [inline]
 __fpu_restore_sig arch/x86/kernel/fpu/signal.c:317 [inline]
 fpu__restore_sig+0x203/0xf50 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: 0033:0x7efff9221929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007efff70680e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007efff9449088 RCX: 00007efff9221929
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007efff9449088
RBP: 00007efff9449080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007efff944908c
R13: 0000000000000000 R14: 00007ffea43802d0 R15: 00007ffea43803b8
 </TASK>