rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=d23c/1/0x4000000000000000 softirq=43884/43885 fqs=2291 rcu: hardirqs softirqs csw/system rcu: number: 1256132 0 0 rcu: cputime: 14006 31348 37 ==> 45370(ms) rcu: (t=10501 jiffies g=53865 q=800 ncpus=2) CPU: 1 PID: 11161 Comm: syz.0.1635 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x2e/0x60 kernel/kcov.c:216 Code: 48 8b 04 24 65 48 8b 0d f0 24 7e 7e 65 8b 15 f1 24 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 <74> 2c 8b 91 f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b RSP: 0018:ffffc900001eee28 EFLAGS: 00000246 RAX: ffffffff813aa470 RBX: 1ffff9200003dded RCX: ffff88802d150000 RDX: 0000000000000100 RSI: 0000000000000002 RDI: 0000000000000001 RBP: ffffc900001eefb8 R08: ffff88802d150000 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900001eef68 R13: dffffc0000000000 R14: 0000000000000000 R15: ffffffff81321d38 FS: 00007f2ca117d6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc6aee03000 CR3: 0000000024431000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: unwind_next_frame+0x130/0x2970 arch/x86/kernel/unwind_orc.c:482 __unwind_start+0x66a/0x7e0 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x280 mm/slub.c:3852 skb_kfree_head net/core/skbuff.c:947 [inline] skb_free_head net/core/skbuff.c:961 [inline] skb_release_data+0x60a/0x800 net/core/skbuff.c:991 skb_release_all net/core/skbuff.c:1057 [inline] __kfree_skb net/core/skbuff.c:1071 [inline] kfree_skb_reason+0x10e/0x170 net/core/skbuff.c:1107 dev_kfree_skb_any_reason+0x10c/0x120 net/core/dev.c:3228 free_old_xmit_skbs+0x114/0x3c0 drivers/net/virtio_net.c:780 start_xmit+0x161/0x1420 drivers/net/virtio_net.c:2420 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3619 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3635 sch_direct_xmit+0x252/0x4a0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:3856 [inline] __dev_queue_xmit+0x173e/0x35a0 net/core/dev.c:4391 dev_queue_xmit include/linux/netdevice.h:3113 [inline] neigh_hh_output include/net/neighbour.h:527 [inline] neigh_output include/net/neighbour.h:541 [inline] ip_finish_output2+0xcd3/0x11d0 net/ipv4/ip_output.c:235 dst_output include/net/dst.h:467 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x10aa/0x1a10 net/ipv4/ip_output.c:535 __tcp_transmit_skb+0x1c97/0x32a0 net/ipv4/tcp_output.c:1422 tcp_rcv_established+0x12e3/0x1cf0 net/ipv4/tcp_input.c:6134 tcp_v4_do_rcv+0x4ed/0xb80 net/ipv4/tcp_ipv4.c:1734 tcp_v4_rcv+0x2334/0x2a50 net/ipv4/tcp_ipv4.c:2166 ip_protocol_deliver_rcu+0x20e/0x3f0 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x2ca/0x510 net/ipv4/ip_input.c:233 NF_HOOK+0x303/0x390 include/linux/netfilter.h:304 dst_input include/net/dst.h:477 [inline] ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline] ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline] ip_sublist_rcv+0xa38/0xd20 net/ipv4/ip_input.c:639 ip_list_rcv+0x3e3/0x430 net/ipv4/ip_input.c:674 __netif_receive_skb_list_ptype net/core/dev.c:5651 [inline] __netif_receive_skb_list_core+0x578/0x740 net/core/dev.c:5699 __netif_receive_skb_list net/core/dev.c:5751 [inline] netif_receive_skb_list_internal+0x91b/0xc60 net/core/dev.c:5842 gro_normal_list include/net/gro.h:451 [inline] gro_normal_one include/net/gro.h:464 [inline] napi_skb_finish net/core/gro.c:573 [inline] napi_gro_receive+0x565/0xb00 net/core/gro.c:603 receive_buf+0x218c/0x3780 drivers/net/virtio_net.c:1870 virtnet_receive drivers/net/virtio_net.c:2155 [inline] virtnet_poll+0x61f/0x1180 drivers/net/virtio_net.c:2229 __napi_poll+0xc0/0x460 net/core/dev.c:6612 napi_poll net/core/dev.c:6679 [inline] net_rx_action+0x5ea/0xbf0 net/core/dev.c:6815 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:generic_exec_single+0x476/0x4f0 kernel/smp.c:418 Code: 75 11 e8 cd e6 0a 00 48 85 db 75 16 e8 c3 e6 0a 00 eb 15 e8 bc e6 0a 00 e8 c7 73 f4 08 48 85 db 74 ea e8 ad e6 0a 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 66 43 c7 44 2c RSP: 0018:ffffc9000546fa00 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff88802d150000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000546fad0 R08: ffffffff90da95ff R09: 1ffffffff21b52bf R10: dffffc0000000000 R11: fffffbfff21b52c0 R12: 1ffff92000a8df44 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff92000a8df65 smp_call_function_single+0x352/0x580 kernel/smp.c:647 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x591/0x8e0 kernel/events/core.c:2948 __do_sys_perf_event_open kernel/events/core.c:12915 [inline] __se_sys_perf_event_open+0x17fa/0x1c20 kernel/events/core.c:12567 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2ca038f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2ca117d038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f2ca05e5fa0 RCX: 00007f2ca038f749 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007f2ca0413f91 R08: 0000000000000002 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2ca05e6038 R14: 00007f2ca05e5fa0 R15: 00007ffcba6ec988