rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 0, t=10502 jiffies, g=7017, q=6 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294967110-4294956607), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10504 jiffies! g7017 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:28736 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5399 [inline] __schedule+0xf15/0x5c00 kernel/sched/core.c:6726 __schedule_loop kernel/sched/core.c:6801 [inline] schedule+0xe7/0x270 kernel/sched/core.c:6816 schedule_timeout+0x136/0x290 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:1631 rcu_gp_kthread+0x245/0x380 kernel/rcu/tree.c:1830 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 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: 5104 Comm: syz-executor207 Not tainted 6.7.0-rc1-next-20231117-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 RIP: 0010:lock_acquire+0xe/0x530 kernel/locking/lockdep.c:5721 Code: e8 07 8f 76 00 8b 74 24 04 e9 23 ff ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 b8 00 00 00 00 00 fc ff df <41> 57 4d 89 cf 41 56 49 89 fe 41 55 41 89 d5 41 54 45 89 c4 55 53 RSP: 0018:ffffc900001f0e68 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8cfd9248 RBP: 000000460022ee80 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000000 R15: 7fffffffffffffff FS: 00005555563d03c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002006b000 CR3: 0000000028789000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: seqcount_lockdep_reader_access include/linux/seqlock.h:102 [inline] ktime_get+0x80/0x490 kernel/time/timekeeping.c:846 clockevents_program_event+0x14b/0x370 kernel/time/clockevents.c:326 tick_program_event+0xa5/0x130 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x36d/0x800 kernel/time/hrtimer.c:1827 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x10c/0x410 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202 Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 6a c8 e3 f6 48 89 df e8 22 40 e4 f6 e8 7d 25 0a f7 fb bf 01 00 00 00 e2 ed d5 f6 65 8b 05 03 19 7f 75 85 c0 74 02 5b c3 e8 f0 dc 7b RSP: 0018:ffffc90003b07d00 EFLAGS: 00000202 RAX: 0000000003c2a68f RBX: ffff8880766c3780 RCX: 1ffffffff1e31619 RDX: 0000000000000000 RSI: ffffffff8accbfe0 RDI: 0000000000000001 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8f18e357 R11: 0000000000000000 R12: ffff8880766c3c18 R13: 0000000000000021 R14: ffff8880766c3b80 R15: 1ffff92000760faf spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x1879/0x2770 kernel/signal.c:2905 arch_do_signal_or_restart+0x90/0x7e0 arch/x86/kernel/signal.c:309 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11e/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x1e/0x60 kernel/entry/common.c:296 do_syscall_64+0x4d/0x110 arch/x86/entry/common.c:88 entry_SYSCALL_64_after_hwframe+0x62/0x6a RIP: 0033:0x7fcf276fe549 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 19 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:00007ffef461c3b8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007fcf276fe549 RDX: 000000002006b000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00007fcf276be990 R09: 00007fcf276be990 R10: 0000000000000000 R11: 0000000000000246 R12: 00005555563d0370 R13: 0000000000000005 R14: 00007ffef461c3f0 R15: 0000000000000000 INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.377 msecs