rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=41781, q=139) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294984227-4294973725), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g41781 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:27776 pid: 15 ppid: 2 flags:0x00004000 Call Trace: 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 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: 9812 Comm: syz.1.1112 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:kasan_mem_to_shadow include/linux/kasan.h:55 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x3d/0x290 mm/kasan/generic.c:189 Code: 49 01 f0 0f 82 57 02 00 00 49 89 f8 49 c1 e8 2f 41 81 f8 ff ff 01 00 0f 82 43 02 00 00 49 bf 01 00 00 00 00 fc ff df 49 89 fb <49> c1 eb 03 49 b8 00 00 00 00 00 fc ff df 4f 8d 0c 03 48 8d 5c 37 RSP: 0018:ffffc900000077c0 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000015 RCX: ffffffff815c0ddf RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffbb0c0 RBP: ffffc90000007a30 R08: 000000000001ffff R09: fffffbfff1ff761b R10: fffffbfff1ff761b R11: ffffffff8ffbb0c0 R12: 000000004fe9651b R13: ffff888025b99dc0 R14: 00000000df81e530 R15: dffffc0000000001 FS: 00007f2764cf06c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32311ff8 CR3: 0000000061e7d000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 000000000000000e DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] hlock_class kernel/locking/lockdep.c:197 [inline] __lock_acquire+0x10af/0x7c60 kernel/locking/lockdep.c:5008 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162 __lock_task_sighand+0x12a/0x290 kernel/signal.c:1404 lock_task_sighand include/linux/sched/signal.h:710 [inline] send_sigqueue+0x177/0x620 kernel/signal.c:1975 posix_timer_event kernel/time/posix-timers.c:360 [inline] posix_timer_fn+0x16a/0x3d0 kernel/time/posix-timers.c:386 __run_hrtimer kernel/time/hrtimer.c:1690 [inline] __hrtimer_run_queues+0x53d/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 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 a6 15 9f f7 65 8b 05 a7 13 50 76 85 c0 74 02 5b c3 e8 54 1e 4e RSP: 0018:ffffc9000380fbc0 EFLAGS: 00000282 RAX: a540dfa8bd34d700 RBX: ffff88802be3dc80 RCX: a540dfa8bd34d700 RDX: dffffc0000000000 RSI: ffffffff8a0b1620 RDI: 0000000000000001 RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed10057c7b91 R10: ffffed10057c7b91 R11: 1ffff110057c7b90 R12: ffff88802be3dc80 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: 0033:0x7f2766aa9be7 Code: ff ff 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 RSP: 002b:00007f2764cf00e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f2766ce1098 RCX: 00007f2766aa9be9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2766ce1098 RBP: 00007f2766ce1090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2766ce1128 R14: 00007fffb6a443d0 R15: 00007fffb6a444b8