rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=3e2/1/0x4000000000000002 softirq=299512/299513 fqs=5249 rcu: (t=10501 jiffies g=378717 q=117508) NMI backtrace for cpu 0 CPU: 0 PID: 15290 Comm: syz-executor.0 Not tainted 5.1.0-rc5+ #146 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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.c:1223 print_cpu_stall kernel/rcu/tree.c:1360 [inline] check_cpu_stall kernel/rcu/tree.c:1434 [inline] rcu_pending kernel/rcu/tree.c:3103 [inline] rcu_sched_clock_irq.cold+0x500/0xa4a kernel/rcu/tree.c:2544 update_process_times+0x32/0x80 kernel/time/timer.c:1635 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161 tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline] smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:kasan_check_read+0x11/0x20 mm/kasan/common.c:103 Code: 59 88 f7 da e8 14 33 b2 ff e9 b4 f5 ff ff 90 90 90 90 90 90 90 90 90 90 90 55 89 f6 31 d2 48 89 e5 48 8b 4d 08 e8 cf 23 00 00 <5d> c3 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 55 89 f6 ba 01 00 00 RSP: 0018:ffff888088e6f3e0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: ffffed10137b6015 RBX: dffffc0000000000 RCX: ffffffff833098d1 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88809bdb00a0 RBP: ffff888088e6f3e0 R08: 1ffff110137b6014 R09: ffffed10137b6015 R10: ffffed10137b6014 R11: ffff88809bdb00a3 R12: ffff88809bdb00a0 R13: ffff888088e6f460 R14: ffff888088e6f840 R15: 1ffff110111cde80 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] refcount_inc_not_zero_checked+0x81/0x200 lib/refcount.c:123 xfrm_pol_hold_rcu net/xfrm/xfrm_policy.c:185 [inline] xfrm_sk_policy_lookup+0x2b5/0x510 net/xfrm/xfrm_policy.c:2178 xfrm_lookup_with_ifid+0x1de/0x1ce0 net/xfrm/xfrm_policy.c:3038 xfrm_lookup net/xfrm/xfrm_policy.c:3175 [inline] xfrm_lookup_route+0x3b/0x1f0 net/xfrm/xfrm_policy.c:3186 ip6_dst_lookup_flow+0x189/0x220 net/ipv6/ip6_output.c:1100 inet6_csk_route_socket+0x85d/0xf40 net/ipv6/inet6_connection_sock.c:110 inet6_csk_xmit+0x110/0x5d0 net/ipv6/inet6_connection_sock.c:125 l2tp_xmit_core net/l2tp/l2tp_core.c:1033 [inline] l2tp_xmit_skb+0x1114/0x13e0 net/l2tp/l2tp_core.c:1135 pppol2tp_sendmsg+0x4a2/0x6b0 net/l2tp/l2tp_ppp.c:329 sock_sendmsg_nosec net/socket.c:651 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:661 ___sys_sendmsg+0x3e2/0x930 net/socket.c:2279 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2374 __do_sys_sendmmsg net/socket.c:2403 [inline] __se_sys_sendmmsg net/socket.c:2400 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2400 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458c29 Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 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 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f3b785d7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000458c29 RDX: 04000000000004ae RSI: 0000000020005fc0 RDI: 0000000000000004 RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f3b785d86d4 R13: 00000000004c5e19 R14: 00000000004da5e0 R15: 00000000ffffffff