rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=5853, q=23 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294962653-4294952151), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g5853 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:26400 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 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: 3591 Comm: syz-executor181 Not tainted 6.1.87-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x7c/0x80 kernel/kcov.c:306 Code: 8d 42 28 4c 39 c8 77 22 89 f8 89 f6 49 ff c2 4c 89 11 48 c7 44 0a 08 05 00 00 00 48 89 44 0a 10 48 89 74 0a 18 4c 89 44 0a 20 0f 1f 00 4c 8b 04 24 65 48 8b 0d f4 db 77 7e 65 8b 05 f5 db 77 RSP: 0018:ffffc900001e0bb0 EFLAGS: 00000046 RAX: 0000000080010003 RBX: 0000000000400140 RCX: ffff888021a8d940 RDX: ffff888021a8d940 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000100000000 R08: ffffffff81569651 R09: ffffffff8156921c R10: 0000000000000002 R11: ffff888021a8d940 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff888021a8d940 R15: 0000000000000001 FS: 00005555560de480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002006b000 CR3: 00000000789d1000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: wants_signal kernel/signal.c:990 [inline] complete_signal+0xf1/0xbd0 kernel/signal.c:1013 send_sigqueue+0x44f/0x720 kernel/signal.c:2003 posix_timer_event kernel/time/posix-timers.c:354 [inline] posix_timer_fn+0x186/0x390 kernel/time/posix-timers.c:380 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: c1 bc f5 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 3e be d5 f6 48 89 df e8 a6 fb d6 f6 e8 71 86 fc f6 fb bf 01 00 00 00 56 88 c9 f6 65 8b 05 f7 a3 6d 75 85 c0 74 02 5b c3 e8 24 c9 6b RSP: 0018:ffffc90003c5fb30 EFLAGS: 00000286 RAX: ee5838433330ca00 RBX: ffff888027e83780 RCX: ffffffff91c92103 RDX: dffffc0000000000 RSI: ffffffff8aec01c0 RDI: 0000000000000001 RBP: ffffc90003c5fc70 R08: dffffc0000000000 R09: ffffed1004fd06f1 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11004fd0783 R13: 000000001c000004 R14: 0000000000000021 R15: ffff888027e83c18 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x154b/0x17d0 kernel/signal.c:2865 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 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+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f511d30a6e9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 1d 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd85ceeae8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f511d30a6e9 RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000000f4240 R08: 00007ffd85ceecf0 R09: 00007ffd85ceecf0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd85ceecf0 R13: 00005555560de430 R14: 00007ffd85ceec10 R15: 00007ffd85ceec00