netlink: 168 bytes leftover after parsing attributes in process `syz-executor4'. rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10501 ticks this GP) idle=afe/1/0x4000000000000002 softirq=379945/379945 fqs=0 rcu: (t=10502 jiffies g=578117 q=1613) rcu: rcu_preempt kthread starved for 10503 jiffies! g578117 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: RCU grace-period kthread stack dump: rcu_preempt I25448 10 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2831 [inline] __schedule+0x897/0x1e90 kernel/sched/core.c:3472 schedule+0xfe/0x350 kernel/sched/core.c:3516 schedule_timeout+0x14a/0x250 kernel/time/timer.c:1803 rcu_gp_fqs_loop+0x6ba/0x970 kernel/rcu/tree.c:1948 rcu_gp_kthread+0x2bb/0xc10 kernel/rcu/tree.c:2105 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 NMI backtrace for cpu 0 CPU: 0 PID: 16378 Comm: syz-executor0 Not tainted 4.20.0+ #12 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+0x1db/0x2d0 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:1211 print_cpu_stall.cold+0x227/0x40c kernel/rcu/tree.c:1348 check_cpu_stall kernel/rcu/tree.c:1422 [inline] rcu_pending kernel/rcu/tree.c:3018 [inline] rcu_check_callbacks+0xb32/0x1380 kernel/rcu/tree.c:2521 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+0x3a7/0x1050 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+0x18d/0x760 arch/x86/kernel/apic/apic.c:1060 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807 RIP: 0010:__sanitizer_cov_trace_pc+0x4b/0x50 kernel/kcov.c:111 Code: 90 d8 12 00 00 83 fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 00 00 48 8b 11 48 83 c2 01 48 39 d0 76 07 48 89 34 d1 48 89 11 <5d> c3 0f 1f 00 65 4c 8b 04 25 40 ee 01 00 65 8b 05 20 f8 7f 7e a9 RSP: 0018:ffff8880a05470d8 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc90005dd1000 RDX: 0000000000040000 RSI: ffffffff86be28d6 RDI: 0000000000000004 RBP: ffff8880a05470d8 R08: ffff88809822c480 R09: 0000000000000000 R10: ffff88809822c480 R11: 0000000000000000 R12: ffff88806a50f200 R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000 __xfrm_policy_bysel_ctx.constprop.0+0x1d6/0x470 net/xfrm/xfrm_policy.c:1621 xfrm_policy_bysel_ctx+0x944/0x1020 net/xfrm/xfrm_policy.c:1664 xfrm_get_policy+0x67b/0x1160 net/xfrm/xfrm_user.c:1887 xfrm_user_rcv_msg+0x458/0x8d0 net/xfrm/xfrm_user.c:2663 netlink_rcv_skb+0x17d/0x410 net/netlink/af_netlink.c:2477 xfrm_netlink_rcv+0x70/0x90 net/xfrm/xfrm_user.c:2671 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] netlink_unicast+0x574/0x770 net/netlink/af_netlink.c:1336 netlink_sendmsg+0xa05/0xf90 net/netlink/af_netlink.c:1917 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg+0xdd/0x130 net/socket.c:631 ___sys_sendmsg+0x7ec/0x910 net/socket.c:2116 __sys_sendmsg+0x112/0x270 net/socket.c:2154 __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg net/socket.c:2161 [inline] __x64_sys_sendmsg+0x78/0xb0 net/socket.c:2161 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: 6d b7 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 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007efe5952cc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 000000002014f000 RDI: 0000000000000003 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007efe5952d6d4 R13: 00000000004c5394 R14: 00000000004d8e30 R15: 00000000ffffffff rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-... } 10689 jiffies s: 78089 root: 0x1/. rcu: blocking rcu_node structures: Task dump for CPU 0: syz-executor0 R running task 26184 16378 7952 0x8000000e Call Trace: