rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=145677, q=31 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4295113836-4295103333), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10504 jiffies! g145677 f0x2 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:26912 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730
 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock_irqrestore+0xf6/0x100 kernel/locking/spinlock.c:194
 try_to_del_timer_sync+0x165/0x1b0 kernel/time/timer.c:1318
 timer_delete_sync+0x1de/0x2a0 kernel/time/timer.c:1466
 del_timer_sync include/linux/timer.h:198 [inline]
 schedule_timeout+0x164/0x280 kernel/time/timer.c:1966
 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
 kthread+0x29d/0x330 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </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: 23335 Comm: syz.5.5538 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:360 [inline]
RIP: 0010:unwind_next_frame+0xb21/0x20b0 arch/x86/kernel/unwind_orc.c:539
Code: c0 20 c8 3c 01 0f 85 9f 0d 00 00 48 89 ef e8 16 1f 00 00 49 89 c7 49 bd 00 00 00 00 00 fc ff df 48 8b 44 24 28 42 80 3c 28 00 <4c> 8b 74 24 08 74 08 4c 89 f7 e8 70 82 98 00 4d 89 3e 48 8b 44 24
RSP: 0018:ffffc90004d475f0 EFLAGS: 00000046
RAX: 1ffff920009a8ee2 RBX: ffffc90004d476c8 RCX: 1ffff920009a8e01
RDX: ffffc90004d47b18 RSI: ffffffff8e3633f8 RDI: ffffc90004d47b10
RBP: ffffc90004d47b10 R08: 0000000000000007 R09: 0000000000000004
R10: fffff520009a8ee5 R11: 1ffff920009a8ee3 R12: 1ffff920009a8eda
R13: dffffc0000000000 R14: ffffc90004d40000 R15: ffffffff81504239
FS:  00007f3ab41716c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3ab35d6098 CR3: 000000004ae22000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1729 [inline]
 slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755
 slab_free mm/slub.c:3687 [inline]
 kmem_cache_free+0xf7/0x290 mm/slub.c:3709
 __sigqueue_free kernel/signal.c:459 [inline]
 collect_signal kernel/signal.c:602 [inline]
 __dequeue_signal+0x4e9/0x610 kernel/signal.c:624
 dequeue_signal+0xe5/0x4b0 kernel/signal.c:647
 get_signal+0x547/0x1350 kernel/signal.c:2751
 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f3ab338eba9
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:00007f3ab41710e8 EFLAGS: 00000246
RAX: fffffffffffffffc RBX: 00007f3ab35d6098 RCX: 00007f3ab338eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f3ab35d6098
RBP: 00007f3ab35d6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3ab35d6128 R14: 00007ffd8c3fb350 R15: 00007ffd8c3fb438
 </TASK>