Re: [syzbot] KASAN: use-after-free Read in mas_next_nentry

[Dmitry Vyukov]

On Thu, 26 Jan 2023 at 14:14, Liam R. Howlett <Liam.Howlett@xxxxxxxxxx> wrote:
>
> syz fix: fs/userfaultfd: Fix maple tree iterator in userfaultfd_unregister()
>
> * syzbot <syzbot+7170d66493145b71afd4@xxxxxxxxxxxxxxxxxxxxxxxxx> [230125 17:04]:
> > syzbot suspects this issue was fixed by commit:

syzbot needs the hash to parse the command:

#syz fix: fs/userfaultfd: Fix maple tree iterator in userfaultfd_unregister()

> > commit 59f2f4b8a757412fce372f6d0767bdb55da127a8
> > Author: Liam Howlett <liam.howlett@xxxxxxxxxx>
> > Date:   Mon Nov 7 20:11:42 2022 +0000
> >
> >     fs/userfaultfd: Fix maple tree iterator in userfaultfd_unregister()
> >
> > bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=129e8afe480000
> > start commit:   b229b6ca5abb Merge tag 'perf-tools-fixes-for-v6.1-2022-10-..
> > git tree:       upstream
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=a66c6c673fb555e8
> > dashboard link: https://syzkaller.appspot.com/bug?extid=7170d66493145b71afd4
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11bfb2a9880000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10b1d319880000
> >
> > If the result looks correct, please mark the issue as fixed by replying with:
> >
> > #syz fix: fs/userfaultfd: Fix maple tree iterator in userfaultfd_unregister()
> >
> > For information about bisection process see: https://goo.gl/tpsmEJ#bisection