Re: [syzbot] Re: [syzbot] [kvm?] WARNING in mmu_free_root_page

[syzbot]

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Subject: Re: [syzbot] [kvm?] WARNING in mmu_free_root_page
Author: phind.uet@xxxxxxxxx

On 3/29/2024 11:55 AM, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    928a87efa423 Merge tag 'gfs2-v6.8-fix' of git://git.kernel..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=127c0546180000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=f64ec427e98bccd7
> dashboard link: https://syzkaller.appspot.com/bug?extid=dc308fcfcd53f987de73
> compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=110481f1180000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=177049a5180000
> 
> Downloadable assets:
> disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-928a87ef.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/7979568a5a16/vmlinux-928a87ef.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/1bc6e1d480e3/bzImage-928a87ef.xz
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+dc308fcfcd53f987de73@xxxxxxxxxxxxxxxxxxxxxxxxx
> 
> ------------[ cut here ]------------
> WARNING: CPU: 0 PID: 5187 at arch/x86/kvm/mmu/mmu.c:3579 mmu_free_root_page+0x36c/0x3f0 arch/x86/kvm/mmu/mmu.c:3579
> Modules linked in:
> CPU: 0 PID: 5187 Comm: syz-executor400 Not tainted 6.9.0-rc1-syzkaller-00005-g928a87efa423 #0
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> RIP: 0010:mmu_free_root_page+0x36c/0x3f0 arch/x86/kvm/mmu/mmu.c:3579
> Code: 00 49 8d 7d 18 be 01 00 00 00 e8 8f 32 c0 09 31 ff 41 89 c6 89 c6 e8 13 e7 6f 00 45 85 f6 0f 85 5d fe ff ff e8 25 ec 6f 00 90 <0f> 0b 90 e9 4f fe ff ff e8 17 ec 6f 00 90 0f 0b 90 e9 79 fe ff ff
> RSP: 0018:ffffc90002fb7700 EFLAGS: 00010293
> RAX: 0000000000000000 RBX: ffff88801e0186c8 RCX: ffffffff811d855d
> RDX: ffff888022f9a440 RSI: ffffffff811d856b RDI: 0000000000000005
> RBP: ffff888024c50370 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000000000000 R11: ffffffff938d6090 R12: 1ffff920005f6ee1
> R13: ffffc90000fae000 R14: 0000000000000000 R15: 0000000000000001
> FS:  00007fe2bd3e76c0(0000) GS:ffff88806b000000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000055ccab488ee8 CR3: 000000002d4ee000 CR4: 0000000000352ef0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>   <TASK>
>   kvm_mmu_free_roots+0x621/0x710 arch/x86/kvm/mmu/mmu.c:3631
>   kvm_mmu_unload+0x42/0x150 arch/x86/kvm/mmu/mmu.c:5638
>   kvm_mmu_reset_context arch/x86/kvm/mmu/mmu.c:5596 [inline]
>   kvm_mmu_after_set_cpuid+0x14d/0x300 arch/x86/kvm/mmu/mmu.c:5585
>   kvm_vcpu_after_set_cpuid arch/x86/kvm/cpuid.c:386 [inline]
>   kvm_set_cpuid+0x1ff1/0x3570 arch/x86/kvm/cpuid.c:460
>   kvm_vcpu_ioctl_set_cpuid2+0xe7/0x160 arch/x86/kvm/cpuid.c:527
>   kvm_arch_vcpu_ioctl+0x26b7/0x4310 arch/x86/kvm/x86.c:5946
>   kvm_vcpu_ioctl+0xa2c/0x1090 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4620
>   vfs_ioctl fs/ioctl.c:51 [inline]
>   __do_sys_ioctl fs/ioctl.c:904 [inline]
>   __se_sys_ioctl fs/ioctl.c:890 [inline]
>   __x64_sys_ioctl+0x193/0x220 fs/ioctl.c:890
>   do_syscall_x64 arch/x86/entry/common.c:52 [inline]
>   do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
>   entry_SYSCALL_64_after_hwframe+0x6d/0x75
> RIP: 0033:0x7fe2bd42e06b
> Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
> RSP: 002b:00007fe2bd3e5710 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 00007fe2bd3e5de0 RCX: 00007fe2bd42e06b
> RDX: 00007fe2bd3e5de0 RSI: 000000004008ae90 RDI: 0000000000000006
> RBP: 0000000000000000 R08: 0000000000000007 R09: 00000000000000eb
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000080
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000006
>   </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@xxxxxxxxxxxxxxxx.
> 
> syzbot will keep track of this issue. See:
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> 
> If the report is already addressed, let syzbot know by replying with:
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> 
> If you want syzbot to run the reproducer, reply with:
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> If you attach or paste a git patch, syzbot will apply it before testing.
> 
> If you want to overwrite report's subsystems, reply with:
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> 
> If the report is a duplicate of another one, reply with:
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> 
> If you want to undo deduplication, reply with:
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> 
Shadow TDP

#syz test:
git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master