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From:   Dmitry Vyukov <dvyukov@google.com>
Date:   Wed, 26 Oct 2022 05:25:33 -0700
Message-ID: <CACT4Y+be9iD66uAfnjDW+skos1b1-0vvoc1GxS9_OS0vfCmCRQ@mail.gmail.com>
Subject: Re: [syzbot] WARNING in vcpu_enter_guest (2)
To:     syzbot <syzbot+dbef12497aa912c8e7ba@syzkaller.appspotmail.com>
Cc:     bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com,
        jarkko@kernel.org, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org,
        mingo@redhat.com, pbonzini@redhat.com, seanjc@google.com,
        syzkaller-bugs@googlegroups.com, tglx@linutronix.de, x86@kernel.org
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On Tue, 25 Oct 2022 at 19:08, syzbot
<syzbot+dbef12497aa912c8e7ba@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit:    4dc12f37a8e9 Merge tag 'platform-drivers-x86-v6.1-2' of gi..
> git tree:       upstream
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=113363d2880000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=a66c6c673fb555e8
> dashboard link: https://syzkaller.appspot.com/bug?extid=dbef12497aa912c8e7ba
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=132e84fc880000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10a872f2880000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/7858e54948b9/disk-4dc12f37.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f37bd48d06dc/vmlinux-4dc12f37.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/98114f50afb3/bzImage-4dc12f37.xz
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+dbef12497aa912c8e7ba@syzkaller.appspotmail.com

This will be fixed by the following commit, right?

#syz fix:
KVM: x86: Exempt pending triple fault from event injection sanity check

https://lore.kernel.org/all/20220930230008.1636044-1-seanjc@google.com/

> kvm: KVM_SET_TSS_ADDR need to be called before entering vcpu
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 3603 at arch/x86/kvm/x86.c:10047 kvm_check_and_inject_events arch/x86/kvm/x86.c:10047 [inline]
> WARNING: CPU: 0 PID: 3603 at arch/x86/kvm/x86.c:10047 vcpu_enter_guest+0x92c/0x5a10 arch/x86/kvm/x86.c:10649
> Modules linked in:
> CPU: 0 PID: 3603 Comm: syz-executor122 Not tainted 6.1.0-rc2-syzkaller-00070-g4dc12f37a8e9 #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
> RIP: 0010:kvm_check_and_inject_events arch/x86/kvm/x86.c:10047 [inline]
> RIP: 0010:vcpu_enter_guest+0x92c/0x5a10 arch/x86/kvm/x86.c:10649
> Code: c0 74 06 0f 8e d2 4f 00 00 45 0f b6 b4 24 e8 08 00 00 31 ff 44 89 f6 e8 72 db 6a 00 45 84 f6 0f 84 d4 41 00 00 e8 d4 de 6a 00 <0f> 0b e9 1e 11 00 00 e8 c8 de 6a 00 be 08 00 00 00 4c 89 ff e8 4b
> RSP: 0018:ffffc90003d3fb60 EFLAGS: 00010293
> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: ffff888023d8ba80 RSI: ffffffff8111bdac RDI: 0000000000000001
> RBP: ffffc90003d3fc80 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000001 R11: 000000000008c07e R12: ffff88801c784000
> R13: 0000000000000000 R14: 0000000000000001 R15: ffff88801c784038
> FS:  0000555556d6e300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fffcf8d4d68 CR3: 000000007b6d6000 CR4: 00000000003526f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  vcpu_run arch/x86/kvm/x86.c:10951 [inline]
>  kvm_arch_vcpu_ioctl_run+0xa5e/0x2b30 arch/x86/kvm/x86.c:11172
>  kvm_vcpu_ioctl+0x570/0xfc0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4065
>  vfs_ioctl fs/ioctl.c:51 [inline]
>  __do_sys_ioctl fs/ioctl.c:870 [inline]
>  __se_sys_ioctl fs/ioctl.c:856 [inline]
>  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
>  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
>  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
>  entry_SYSCALL_64_after_hwframe+0x63/0xcd
> RIP: 0033:0x7f6a646982b9
> Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48
> RSP: 002b:00007fffcf8d6828 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f6a646982b9
> RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
> RBP: 00007f6a6465bd10 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6a6465bda0
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
>  </TASK>
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> syzbot can test patches for this issue, for details see:
> https://goo.gl/tpsmEJ#testing-patches
>
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