rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=5fa/1/0x4000000000000002 softirq=237913/237916 fqs=5182 (t=10500 jiffies g=411817 q=7493) NMI backtrace for cpu 1 CPU: 1 PID: 7862 Comm: syz-executor.1 Not tainted 5.3.0-rc8+ #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+0x172/0x1f0 lib/dump_stack.c:113 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:455 [inline] check_cpu_stall kernel/rcu/tree_stall.h:529 [inline] rcu_pending kernel/rcu/tree.c:2736 [inline] rcu_sched_clock_irq.cold+0x4dd/0xc13 kernel/rcu/tree.c:2183 update_process_times+0x32/0x80 kernel/time/timer.c:1639 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1296 __run_hrtimer kernel/time/hrtimer.c:1389 [inline] __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1451 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830 RIP: 0010:hhf_dequeue+0x9f/0xa20 net/sched/sch_hhf.c:434 Code: e8 36 1a ac fb 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 0f 85 6d 07 00 00 49 8b 1e 48 8d 7b 10 48 89 f8 48 c1 e8 03 42 0f b6 04 20 <84> c0 74 08 3c 03 0f 8e 69 07 00 00 44 8b 7b 10 31 ff 44 89 fe e8 RSP: 0018:ffff88807bfbefe8 EFLAGS: 00000a06 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000000 RBX: ffff888097b099b8 RCX: ffffc90008e5d000 RDX: 0000000000040000 RSI: ffffffff85c65afa RDI: ffff888097b099c8 RBP: ffff88807bfbf038 R08: ffff88805dbe2500 R09: 0000000000000000 R10: fffffbfff134afaf R11: ffff88805dbe2500 R12: dffffc0000000000 R13: ffff888097b096c0 R14: ffff888097b09a50 R15: ffff888097b09a50 dequeue_skb net/sched/sch_generic.c:258 [inline] qdisc_restart net/sched/sch_generic.c:361 [inline] __qdisc_run+0x1e7/0x19d0 net/sched/sch_generic.c:379 __dev_xmit_skb net/core/dev.c:3533 [inline] __dev_queue_xmit+0x16f1/0x3650 net/core/dev.c:3838 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 br_dev_queue_push_xmit+0x3f3/0x5c0 net/bridge/br_forward.c:52 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] br_forward_finish+0xfa/0x400 net/bridge/br_forward.c:65 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] __br_forward+0x641/0xb00 net/bridge/br_forward.c:109 deliver_clone+0x61/0xc0 net/bridge/br_forward.c:125 maybe_deliver+0x2c7/0x390 net/bridge/br_forward.c:181 br_flood+0x13a/0x3d0 net/bridge/br_forward.c:223 br_dev_xmit+0xcab/0x15a0 net/bridge/br_device.c:104 __netdev_start_xmit include/linux/netdevice.h:4406 [inline] netdev_start_xmit include/linux/netdevice.h:4420 [inline] xmit_one net/core/dev.c:3280 [inline] dev_hard_start_xmit+0x1a3/0x9c0 net/core/dev.c:3296 __dev_queue_xmit+0x2b15/0x3650 net/core/dev.c:3869 dev_queue_xmit+0x18/0x20 net/core/dev.c:3902 pppoe_sendmsg+0x661/0x7f0 drivers/net/ppp/pppoe.c:899 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:657 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311 __sys_sendmmsg+0x2db/0x4d0 net/socket.c:2406 __compat_sys_sendmmsg net/compat.c:656 [inline] __do_compat_sys_sendmmsg net/compat.c:663 [inline] __se_compat_sys_sendmmsg net/compat.c:660 [inline] __ia32_compat_sys_sendmmsg+0x9f/0x100 net/compat.c:660 do_syscall_32_irqs_on arch/x86/entry/common.c:332 [inline] do_fast_syscall_32+0x27b/0xdb3 arch/x86/entry/common.c:403 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f78a29 Code: b8 80 96 98 00 eb cc 8b 04 24 c3 8b 1c 24 c3 8b 34 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f5d740cc EFLAGS: 00000296 ORIG_RAX: 0000000000000159 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000002000d180 RDX: 000000000000001a RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000