rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10500 ticks this GP) idle=7fa/1/0x4000000000000004 softirq=46381/46381 fqs=0 (t=10501 jiffies g=50077 q=397) rcu: rcu_preempt kthread starved for 10502 jiffies! g50077 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt R running task 29264 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3386 [inline] __schedule+0x934/0x1f90 kernel/sched/core.c:4082 schedule+0xdc/0x2b0 kernel/sched/core.c:4156 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1658 [inline] rcu_gp_kthread+0xa10/0x1940 kernel/rcu/tree.c:1818 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 1 CPU: 1 PID: 23522 Comm: syz-executor.4 Not tainted 5.5.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree_stall.h:254 print_cpu_stall kernel/rcu/tree_stall.h:475 [inline] check_cpu_stall kernel/rcu/tree_stall.h:549 [inline] rcu_pending kernel/rcu/tree.c:3030 [inline] rcu_sched_clock_irq.cold+0x51a/0xc37 kernel/rcu/tree.c:2276 update_process_times+0x2d/0x70 kernel/time/timer.c:1726 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:171 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1314 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1119 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1144 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x4f/0x80 kernel/locking/spinlock.c:199 Code: c0 c8 b0 b3 89 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 33 48 83 3d 52 5e c5 01 00 74 20 fb 66 0f 1f 44 00 00 01 00 00 00 e8 07 82 62 f9 65 8b 05 f8 cb 13 78 85 c0 74 06 41 RSP: 0018:ffffc90000da8dd0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff1367619 RBX: ffffffff86509890 RCX: 0000000000000002 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff8880a75fc8d4 RBP: ffffc90000da8dd8 R08: 1ffffffff16a2f6d R09: fffffbfff16a2f6e R10: fffffbfff16a2f6d R11: ffffffff8b517b6f R12: ffff8880ae927400 R13: ffff888094816418 R14: ffff8880ae927400 R15: dffffc0000000000 expire_timers kernel/time/timer.c:1448 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x6b1/0x1790 kernel/time/timer.c:1786 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:546 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1146 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline] RIP: 0010:lock_acquire+0x20b/0x410 kernel/locking/lockdep.c:4487 Code: 94 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 d3 01 00 00 48 83 3d d9 83 58 08 00 0f 84 53 01 00 00 48 8b 7d c8 57 9d <0f> 1f 44 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 65 8b RSP: 0018:ffffc90004d57460 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff1367617 RBX: ffff8880a75fc040 RCX: ffffffff815ae042 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000282 RBP: ffffc90004d574a8 R08: 0000000000004462 R09: fffffbfff16a2f6e R10: ffff8880a75fc900 R11: ffff8880a75fc040 R12: ffff88809238f358 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2f/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:338 [inline] d_alloc+0x6d/0x280 fs/dcache.c:1772 d_alloc_parallel+0xf4/0x1c00 fs/dcache.c:2521 __lookup_slow+0x1ab/0x4d0 fs/namei.c:1742 lookup_slow fs/namei.c:1774 [inline] walk_component+0x7ce/0x10b0 fs/namei.c:1915 link_path_walk.part.0+0x9d2/0x1370 fs/namei.c:2241 link_path_walk fs/namei.c:2172 [inline] path_openat+0x1f9/0x3490 fs/namei.c:3606 do_filp_open+0x192/0x260 fs/namei.c:3637 do_sys_openat2+0x5eb/0x7e0 fs/open.c:1149 do_sys_open+0xf2/0x180 fs/open.c:1165 ksys_open include/linux/syscalls.h:1386 [inline] __do_sys_open fs/open.c:1171 [inline] __se_sys_open fs/open.c:1169 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1169 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x415131 Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f3bd77f0bb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 00007f3bd77f16d4 RCX: 0000000000415131 RDX: 00000000004047ef RSI: 0000000000000002 RDI: 00007f3bd77f0bd0 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000019 R10: 0000000000000004 R11: 0000000000000293 R12: 00000000ffffffff R13: 0000000000000be6 R14: 00000000004cccd7 R15: 000000000075bf2c