rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=11e/1/0x4000000000000000 softirq=86250/86250 fqs=2 (detected by 1, t=10502 jiffies, g=155181, q=47) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6843 Comm: syz-executor.1 Not tainted 5.9.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_local_save_flags arch/x86/include/asm/paravirt.h:765 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/paravirt.h:787 [inline] RIP: 0010:lock_release+0x126/0x8f0 kernel/locking/lockdep.c:5022 Code: b6 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 13 07 00 00 48 83 3d 22 d6 5b 08 00 0f 84 15 05 00 00 9c 58 <0f> 1f 44 00 00 48 ba 00 00 00 00 00 fc ff df 48 89 04 24 48 c7 c0 RSP: 0018:ffffc90000007d08 EFLAGS: 00000082 RAX: 0000000000000082 RBX: ffff888090f562c0 RCX: 1ffffffff1308b20 RDX: dffffc0000000000 RSI: ffffffff89bd6980 RDI: ffff888090f56ba4 RBP: 1ffff92000000fa3 R08: 0000000000000000 R09: 0000000000000000 R10: fffffbfff1564d71 R11: 0000000000000001 R12: 0000000000000000 R13: ffff8880ae627758 R14: ffffffff81649151 R15: dffffc0000000000 FS: 00000000023b1940(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f822000 CR3: 0000000072238000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_unlock_irqrestore+0x16/0x90 kernel/locking/spinlock.c:191 __run_hrtimer kernel/time/hrtimer.c:1520 [inline] __hrtimer_run_queues+0x5d1/0xfc0 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] sysvec_apic_timer_interrupt+0xb2/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:lock_acquire+0x27b/0xae0 kernel/locking/lockdep.c:5009 Code: ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 04 07 00 00 48 83 3d e8 cb 5b 08 00 0f 84 5a 05 00 00 4c 89 ff 57 9d <0f> 1f 44 00 00 48 b8 00 00 00 00 00 fc ff df 48 03 44 24 08 48 c7 RSP: 0018:ffffc90002b37cd0 EFLAGS: 00000282 RAX: 1ffffffff136c789 RBX: ffff888090f562c0 RCX: ffffffff815a184b RDX: dffffc0000000000 RSI: 0000000000000001 RDI: 0000000000000282 RBP: ffff8880a1b89228 R08: 0000000000000000 R09: ffffffff8c5f59ff R10: fffffbfff18beb3f R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000282 __might_fault mm/memory.c:4870 [inline] __might_fault+0x152/0x1d0 mm/memory.c:4855 _copy_from_user+0x29/0x190 lib/usercopy.c:12 copy_from_user include/linux/uaccess.h:160 [inline] get_timespec64+0x75/0x220 kernel/time/time.c:787 __do_sys_nanosleep kernel/time/hrtimer.c:1962 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:1957 [inline] __x64_sys_nanosleep+0xaa/0x260 kernel/time/hrtimer.c:1957 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45ba81 Code: 75 14 b8 23 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 84 cf fb ff c3 48 83 ec 08 e8 ea 46 00 00 48 89 04 24 b8 23 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 33 47 00 00 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fffc4449ca0 EFLAGS: 00000293 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 00000000000e424b RCX: 000000000045ba81 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fffc4449cb0 RBP: 0000000000000b0e R08: 0000000000000000 R09: 00000000023b1940 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 00007fffc4449d00 R14: 00000000000e424b R15: 00007fffc4449d10 rcu: rcu_preempt kthread starved for 10498 jiffies! g155181 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:29216 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0xea9/0x2230 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_timeout+0x148/0x250 kernel/time/timer.c:1879 rcu_gp_fqs_loop kernel/rcu/tree.c:1888 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2058 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294