Re: [moderation/CI] Re: KVM: x86: Destroy the PIC and IOAPIC before destroying vCPUs

#syz upstream

On Tue, Jul 7, 2026 at 8:08 AM syzbot ci
<[email protected]> wrote:
>
> syzbot ci has tested the following series
>
> [v2] KVM: x86: Destroy the PIC and IOAPIC before destroying vCPUs
> https://lore.kernel.org/all/[email protected]
> * [PATCH v2] KVM: x86: Destroy the PIC and IOAPIC before destroying vCPUs
>
> and found the following issue:
> general protection fault in kvm_cpu_has_extint
>
> Full report is available here:
> https://ci.syzbot.org/series/43a61d29-79d6-47db-ac80-4e948bd10c1a
>
> ***
>
> general protection fault in kvm_cpu_has_extint
>
> tree:      kvm-next
> URL:       https://kernel.googlesource.com/pub/scm/virt/kvm/kvm/
> base:      fb402386af4cdce108ff991a796386de55439735
> arch:      amd64
> compiler:  Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6
> config:    https://ci.syzbot.org/builds/7f3721c2-14ce-4beb-aa97-08232f57e71a/config
> syz repro: https://ci.syzbot.org/findings/0522c527-432c-4524-9835-64ab75b899af/syz_repro
>
> Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] SMP KASAN NOPTI
> KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097]
> CPU: 1 UID: 0 PID: 5786 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> RIP: 0010:kvm_cpu_has_extint+0xdb/0x340 arch/x86/kvm/irq.c:83
> Code: c6 e8 0d 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 44 54 e0 00 bb 90 00 00 00 49 03 1e 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 aa 00 00 00 8b 2b eb 6d e8 df 08 76 00
> RSP: 0018:ffffc900032f7740 EFLAGS: 00010206
> RAX: 0000000000000012 RBX: 0000000000000090 RCX: ffff88816b748000
> RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
> RBP: 0000000000000001 R08: ffff88816b748000 R09: 0000000000000006
> R10: 0000000000000006 R11: 0000000000000000 R12: 1ffff1102e032000
> R13: dffffc0000000000 R14: ffff88811e33cde8 R15: dffffc0000000000
> FS:  00007f57357e76c0(0000) GS:ffff8882a9714000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fae800f0378 CR3: 0000000109ffc000 CR4: 0000000000352ef0
> Call Trace:
>  <TASK>
>  kvm_cpu_has_injectable_intr+0x1c/0x170 arch/x86/kvm/irq.c:98
>  __nested_vmx_vmexit+0x1911/0x2b40 arch/x86/kvm/vmx/nested.c:5181
>  nested_vmx_vmexit arch/x86/kvm/vmx/nested.h:46 [inline]
>  vmx_leave_nested arch/x86/kvm/vmx/nested.c:6854 [inline]
>  nested_vmx_free_vcpu+0x8e/0xd0 arch/x86/kvm/vmx/nested.c:381
>  vmx_vcpu_free+0x109/0x2c0 arch/x86/kvm/vmx/vmx.c:7765
>  kvm_arch_vcpu_destroy+0x154/0x380 arch/x86/kvm/x86.c:12859
>  kvm_vcpu_destroy virt/kvm/kvm_main.c:469 [inline]
>  kvm_destroy_vcpus+0x123/0x380 virt/kvm/kvm_main.c:489
>  kvm_arch_destroy_vm+0xf9/0x2c0 arch/x86/kvm/x86.c:13405
>  kvm_destroy_vm virt/kvm/kvm_main.c:1301 [inline]
>  kvm_put_kvm+0x772/0xb10 virt/kvm/kvm_main.c:1338
>  kvm_vcpu_release+0x54/0x60 virt/kvm/kvm_main.c:4101
>  __fput+0x41f/0xa40 fs/file_table.c:469
>  task_work_run+0x1d9/0x270 kernel/task_work.c:233
>  get_signal+0x1181/0x12c0 kernel/signal.c:2807
>  arch_do_signal_or_restart+0xbb/0x810 arch/x86/kernel/signal.c:337
>  __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
>  exit_to_user_mode_loop+0xa3/0x5e0 kernel/entry/common.c:98
>  __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
>  syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
>  syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
>  do_syscall_64+0x357/0xf80 arch/x86/entry/syscall_64.c:100
>  entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f573499ce59
> 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:00007f57357e7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: fffffffffffffffc RBX: 00007f5734c15fa0 RCX: 00007f573499ce59
> RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
> RBP: 00007f5734a32e6f R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007f5734c16038 R14: 00007f5734c15fa0 R15: 00007fffda4d80f8
>  </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:kvm_cpu_has_extint+0xdb/0x340 arch/x86/kvm/irq.c:83
> Code: c6 e8 0d 00 00 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 44 54 e0 00 bb 90 00 00 00 49 03 1e 48 89 d8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 aa 00 00 00 8b 2b eb 6d e8 df 08 76 00
> RSP: 0018:ffffc900032f7740 EFLAGS: 00010206
> RAX: 0000000000000012 RBX: 0000000000000090 RCX: ffff88816b748000
> RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
> RBP: 0000000000000001 R08: ffff88816b748000 R09: 0000000000000006
> R10: 0000000000000006 R11: 0000000000000000 R12: 1ffff1102e032000
> R13: dffffc0000000000 R14: ffff88811e33cde8 R15: dffffc0000000000
> FS:  00007f57357e76c0(0000) GS:ffff8882a9714000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000056532c5e2950 CR3: 0000000109ffc000 CR4: 0000000000352ef0
> ----------------
> Code disassembly (best guess), 1 bytes skipped:
>    0:   e8 0d 00 00 4c          call   0x4c000012
>    5:   89 f0                   mov    %esi,%eax
>    7:   48 c1 e8 03             shr    $0x3,%rax
>    b:   42 80 3c 38 00          cmpb   $0x0,(%rax,%r15,1)
>   10:   74 08                   je     0x1a
>   12:   4c 89 f7                mov    %r14,%rdi
>   15:   e8 44 54 e0 00          call   0xe0545e
>   1a:   bb 90 00 00 00          mov    $0x90,%ebx
>   1f:   49 03 1e                add    (%r14),%rbx
>   22:   48 89 d8                mov    %rbx,%rax
>   25:   48 c1 e8 03             shr    $0x3,%rax
> * 29:   42 0f b6 04 38          movzbl (%rax,%r15,1),%eax <-- trapping instruction
>   2e:   84 c0                   test   %al,%al
>   30:   0f 85 aa 00 00 00       jne    0xe0
>   36:   8b 2b                   mov    (%rbx),%ebp
>   38:   eb 6d                   jmp    0xa7
>   3a:   e8 df 08 76 00          call   0x76091e
>
>
> ***
>
> If these findings have caused you to resend the series or submit a
> separate fix, please add the following tag to your commit message:
>   Tested-by: [email protected]
>
> ---
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