rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=148005, q=74) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295082407-4295071905), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g148005 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:27152 pid: 15 ppid: 2 flags:0x00004000 Call Trace: 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 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: 28126 Comm: syz.2.7032 Not tainted 5.15.182-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:134 [inline] RIP: 0010:lock_acquire+0x1d1/0x3f0 kernel/locking/lockdep.c:5626 Code: b8 ff ff ff ff 65 0f c1 05 cc 95 a6 7e 83 f8 01 0f 85 fa 00 00 00 48 c7 84 24 80 00 00 00 00 00 00 00 9c 8f 84 24 80 00 00 00 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 RSP: 0018:ffffc90000dd0c60 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000000 RCX: e278c44d7954b100 RDX: 0000000000000000 RSI: ffffffff8a0b2260 RDI: ffffffff8a59a2c0 RBP: ffffc90000dd0d68 R08: dffffc0000000000 R09: fffffbfff1ff341a R10: fffffbfff1ff341a R11: 1ffffffff1ff3419 R12: ffffffff8c12e688 R13: 1ffff920001ba198 R14: 0000000000000046 R15: dffffc0000000000 FS: 00007f3d693326c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000055313000 CR4: 00000000003506e0 DR0: 0000000000000002 DR1: 400000000000000c DR2: 000000000000000d DR3: 00000010000000fb DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: seqcount_lockdep_reader_access+0xc6/0x1c0 include/linux/seqlock.h:103 ktime_get+0x31/0x270 kernel/time/timekeeping.c:829 clockevents_program_event+0xe2/0x310 kernel/time/clockevents.c:326 hrtimer_interrupt+0x4de/0x8d0 kernel/time/hrtimer.c:1829 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 4e d6 b1 f7 48 89 df e8 16 ab b2 f7 e8 51 4f d3 f7 fb bf 01 00 00 00 46 cf a6 f7 65 8b 05 e7 e2 57 76 85 c0 74 02 5b c3 e8 94 ed 55 RSP: 0018:ffffc9000338fbc0 EFLAGS: 00000282 RAX: e278c44d7954b100 RBX: ffff888057e15c80 RCX: e278c44d7954b100 RDX: dffffc0000000000 RSI: ffffffff8a0b0fc0 RDI: 0000000000000001 RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed100afc2b91 R10: ffffed100afc2b91 R11: 1ffff1100afc2b90 R12: ffff888057e15c80 R13: 0000000000000011 R14: dffffc0000000000 R15: 0000000004000000 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: 0033:0x7f3d6b4ca969 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:00007f3d693320e8 EFLAGS: 00000246 RAX: fffffffffffffffc RBX: 00007f3d6b6f1fa8 RCX: 00007f3d6b4ca969 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f3d6b6f1fa8 RBP: 00007f3d6b6f1fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3d6b6f1fac R13: 0000000000000000 R14: 00007ffc9e59a3d0 R15: 00007ffc9e59a4b8 vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun