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

[Sean Christopherson]

On Wed, Dec 13, 2023, syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    f2e8a57ee903 Merge tag 'scsi-fixes' of git://git.kernel.or..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=14fdc732e80000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=e56083f7dbe162c2
> dashboard link: https://syzkaller.appspot.com/bug?extid=81227d2bd69e9dedb802
> 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=129d09cae80000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10b8afeee80000
> 
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/7b75e59fc59d/disk-f2e8a57e.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/f853580d61be/vmlinux-f2e8a57e.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/8c893ce02e2c/bzImage-f2e8a57e.xz
> 
> Bisection is inconclusive: the first bad commit could be any of:
> 
> d61ea1cb0095 userfaultfd: UFFD_FEATURE_WP_ASYNC
> 52526ca7fdb9 fs/proc/task_mmu: implement IOCTL to get and optionally clear info about PTEs

#syz fix: fs/proc/task_mmu: move mmu notification mechanism inside mm lock