rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10119 ticks this GP) idle=b114/1/0x4000000000000000 softirq=46217/46220 fqs=5242 rcu: hardirqs softirqs csw/system rcu: number: 1443547 7 0 rcu: cputime: 16897 35601 38 ==> 52520(ms) rcu: (t=10503 jiffies g=62301 q=1073 ncpus=2) CPU: 1 PID: 12175 Comm: syz.0.1945 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x1f/0x60 kernel/kcov.c:216 Code: 89 de 5b e9 d3 67 57 00 cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 60 92 7c 7e 65 8b 15 61 92 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 RSP: 0018:ffffc900001ef770 EFLAGS: 00000206 RAX: ffffffff813b3cc1 RBX: ffffffff8e9e2324 RCX: ffff88802dc0bc00 RDX: 0000000000000100 RSI: ffffffff817bc9fc RDI: ffffffff817bc5e8 RBP: ffffffff8e9e2324 R08: ffffc900001ef910 R09: 0000000000000021 R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff8e9e2328 R13: ffffffff817bc5e8 R14: ffffffff817bc9fc R15: ffffffff8e9e2324 FS: 00007f910cdfe6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 000000005f542000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __orc_find arch/x86/kernel/unwind_orc.c:99 [inline] orc_find arch/x86/kernel/unwind_orc.c:227 [inline] unwind_next_frame+0x501/0x2970 arch/x86/kernel/unwind_orc.c:494 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+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 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+0xf8/0x270 mm/slub.c:3852 dev_kfree_skb_any_reason+0x120/0x130 net/core/dev.c:3241 free_old_xmit_skbs+0x11a/0x3d0 drivers/net/virtio_net.c:780 start_xmit+0x168/0x14a0 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:3644 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3660 sch_direct_xmit+0x25e/0x4c0 net/sched/sch_generic.c:345 __dev_xmit_skb net/core/dev.c:3881 [inline] __dev_queue_xmit+0x165d/0x3660 net/core/dev.c:4416 NF_HOOK+0x331/0x3b0 include/linux/netfilter.h:-1 arp_xmit+0x16c/0x270 net/ipv4/arp.c:664 arp_process+0x13ba/0x17b0 net/ipv4/arp.c:854 NF_HOOK+0x331/0x3b0 include/linux/netfilter.h:-1 __netif_receive_skb_list_ptype net/core/dev.c:5694 [inline] __netif_receive_skb_list_core+0x6ea/0x750 net/core/dev.c:5737 __netif_receive_skb_list net/core/dev.c:5789 [inline] netif_receive_skb_list_internal+0x943/0xca0 net/core/dev.c:5880 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:575 [inline] napi_gro_receive+0x565/0xb00 net/core/gro.c:605 receive_buf+0x2203/0x3820 drivers/net/virtio_net.c:1870 virtnet_receive drivers/net/virtio_net.c:2155 [inline] virtnet_poll+0x5dd/0x1280 drivers/net/virtio_net.c:2229 __napi_poll+0xc0/0x460 net/core/dev.c:6650 napi_poll net/core/dev.c:6717 [inline] net_rx_action+0x616/0xc40 net/core/dev.c:6853 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+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:kvm_kick_cpu+0x78/0xb0 arch/x86/kernel/kvm.c:1036 Code: b4 a4 00 48 c7 c3 d0 19 02 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 84 c0 75 28 0f b7 0b b8 05 00 00 00 31 db 0f 01 c1 <5b> 41 5e 41 5f c3 e8 ed 7c 4c 00 89 de 48 c7 c7 20 df f9 8c e8 1f RSP: 0018:ffffc900195ffb20 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffffc9000ccea000 RSI: 00000000000135de RDI: 00000000000135df RBP: 0000000000000000 R08: ffffc90000a26a0b R09: 1ffff92000144d41 R10: dffffc0000000000 R11: fffff52000144d42 R12: 1ffff11047ffc218 R13: dffffc0000000000 R14: ffffffff8ca77a30 R15: dffffc0000000000 pv_kick kernel/locking/qspinlock_paravirt.h:543 [inline] __pv_queued_spin_unlock_slowpath+0x198/0x2a0 kernel/locking/qspinlock_paravirt.h:543 __raw_callee_save___pv_queued_spin_unlock_slowpath+0x15/0x30 .slowpath+0x9/0x1a pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:57 [inline] do_raw_spin_unlock+0x121/0x230 kernel/locking/spinlock_debug.c:141 __raw_spin_unlock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_unlock+0x1e/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] futex_wake+0x41d/0x4f0 kernel/futex/waitwake.c:183 do_futex+0x35d/0x3e0 kernel/futex/syscalls.c:139 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x3a9/0x440 kernel/futex/syscalls.c:192 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f910bf9ce59 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:00007f910cdfe0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f910c215fa8 RCX: 00007f910bf9ce59 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f910c215fac RBP: 00007f910c215fa0 R08: 0000000000745d1e R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f910c216038 R14: 00007ffdddb7cc30 R15: 00007ffdddb7cd18