rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10485 ticks this GP) idle=9d64/1/0x4000000000000000 softirq=16729/16731 fqs=5249 rcu: hardirqs softirqs csw/system rcu: number: 1556901 0 0 rcu: cputime: 13396 39093 46 ==> 52500(ms) rcu: (t=10502 jiffies g=15689 q=806 ncpus=2) CPU: 1 PID: 7095 Comm: syz.1.367 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 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 e0 d2 7c 7e 65 8b 15 e1 d2 7c 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:ffffc900001ef110 EFLAGS: 00000246 RAX: ffffffff813b5989 RBX: ffffc900001efc18 RCX: ffff88801aaa5a00 RDX: 0000000000000100 RSI: 0000000000000002 RDI: ffffc900001efc18 RBP: ffffc900001efc18 R08: ffff88801aaa5a00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900001f1000 R13: 1ffff9200003de4b R14: ffffc900001e9000 R15: dffffc0000000000 FS: 00007f127b3a86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f23b69ea540 CR3: 000000004dbb8000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __read_once_word_nocheck+0x9/0x10 include/asm-generic/rwonce.h:66 deref_stack_reg+0x1ab/0x230 arch/x86/kernel/unwind_orc.c:406 unwind_next_frame+0x1781/0x2990 arch/x86/kernel/unwind_orc.c:648 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] kmem_cache_free+0xf8/0x290 mm/slub.c:3852 kfree_skb include/linux/skbuff.h:1264 [inline] packet_rcv_fanout+0xdf/0x680 net/packet/af_packet.c:1518 dev_queue_xmit_nit+0xb0c/0xba0 net/core/dev.c:2385 xmit_one net/core/dev.c:3640 [inline] dev_hard_start_xmit+0x150/0x790 net/core/dev.c:3660 __dev_queue_xmit+0x198c/0x3630 net/core/dev.c:4454 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+0xd4f/0x1260 net/ipv4/ip_output.c:235 NF_HOOK_COND include/linux/netfilter.h:293 [inline] ip_output+0x2a5/0x3a0 net/ipv4/ip_output.c:436 dst_output include/net/dst.h:467 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] ip_send_skb+0x12f/0x1d0 net/ipv4/ip_output.c:1498 __icmp_send+0x1100/0x1430 net/ipv4/icmp.c:801 ipv4_send_dest_unreach net/ipv4/route.c:1263 [inline] ipv4_link_failure+0x638/0xa20 net/ipv4/route.c:1270 dst_link_failure include/net/dst.h:437 [inline] vti_xmit net/ipv4/ip_vti.c:268 [inline] vti_tunnel_xmit+0xe0f/0x1620 net/ipv4/ip_vti.c:304 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3644 [inline] dev_hard_start_xmit+0x269/0x790 net/core/dev.c:3660 __dev_queue_xmit+0x198c/0x3630 net/core/dev.c:4454 neigh_output include/net/neighbour.h:543 [inline] ip_finish_output2+0xd97/0x1260 net/ipv4/ip_output.c:235 NF_HOOK_COND include/linux/netfilter.h:293 [inline] ip_output+0x2a5/0x3a0 net/ipv4/ip_output.c:436 dst_output include/net/dst.h:467 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x1056/0x1960 net/ipv4/ip_output.c:540 __tcp_transmit_skb+0x1dd6/0x3470 net/ipv4/tcp_output.c:1427 tcp_transmit_skb net/ipv4/tcp_output.c:1445 [inline] __tcp_retransmit_skb+0x9d8/0x1410 net/ipv4/tcp_output.c:3379 tcp_retransmit_skb+0x32/0x360 net/ipv4/tcp_output.c:3402 tcp_retransmit_timer+0x18e7/0x3030 net/ipv4/tcp_timer.c:603 tcp_write_timer+0x12a/0x280 net/ipv4/tcp_timer.c:709 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x570/0x810 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x27d/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 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:finish_task_switch+0x267/0x8f0 kernel/sched/core.c:5255 Code: 26 09 85 c0 0f 84 30 01 00 00 48 85 db 0f 85 4f 01 00 00 0f 1f 44 00 00 4c 89 e7 e8 93 3b 30 09 e8 7e 0b 30 00 fb 4c 8b 65 b8 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 RSP: 0018:ffffc9000c4f76e0 EFLAGS: 00000282 RAX: 6feca148acd7a400 RBX: 0000000000000000 RCX: 6feca148acd7a400 RDX: dffffc0000000000 RSI: ffffffff8acacb60 RDI: ffffffff8b1c7be0 RBP: ffffc9000c4f7730 R08: ffffffff911bc5ff R09: 1ffffffff22378bf R10: dffffc0000000000 R11: fffffbfff22378c0 R12: ffff88801aaa5a00 R13: 1ffff110171e79a9 R14: dffffc0000000000 R15: ffff8880b8f3cd48 context_switch kernel/sched/core.c:5384 [inline] __schedule+0x15b6/0x4660 kernel/sched/core.c:6700 preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:preempt_count_sub+0x65/0x160 kernel/sched/core.c:5885 Code: ff ff ff 7f 39 cf 7f 25 81 ff ff 00 00 00 0f 93 c1 84 c0 0f 95 c0 08 c8 74 53 65 8b 05 7c 4e a7 7e f7 df 65 01 3d 73 4e a7 7e <5b> 5d c3 e8 03 79 c9 02 85 c0 74 f4 48 c7 c0 a0 1a 8b 8e 48 c1 e8 RSP: 0018:ffffc9000c4f7ac8 EFLAGS: 00000257 RAX: 0000000000000001 RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffffc9000c669000 RSI: 0000000000007183 RDI: 00000000ffffffff RBP: ffffc9000c4f7bd0 R08: ffffffff911bc5ff R09: 1ffffffff22378bf R10: dffffc0000000000 R11: fffffbfff22378c0 R12: 0000000000000000 R13: dffffc0000000000 R14: 1ffff9200189ef60 R15: 1ffff9200189ef60 smp_call_function_single+0x406/0x5a0 kernel/smp.c:652 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x5bb/0x920 kernel/events/core.c:2951 __do_sys_perf_event_open kernel/events/core.c:12949 [inline] __se_sys_perf_event_open+0x1841/0x1c60 kernel/events/core.c:12601 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f127a59ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f127b3a8028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f127a815fa0 RCX: 00007f127a59ce59 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000480 RBP: 00007f127a632e6f R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f127a816038 R14: 00007f127a815fa0 R15: 00007ffd57de5ef8