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From:   Jann Horn <jannh@google.com>
Date:   Fri, 24 Nov 2023 16:26:02 +0100
Message-ID: <CAG48ez2_XT1XDML756zM2D07BjcJnw22pFiHHrOm-yHvGJHvdw@mail.gmail.com>
Subject: Re: [syzbot] [overlayfs?] KASAN: invalid-free in ovl_copy_up_one
To:     amir73il@gmail.com,
        syzbot <syzbot+477d8d8901756d1cbba1@syzkaller.appspotmail.com>
Cc:     linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-unionfs@vger.kernel.org, miklos@szeredi.hu,
        syzkaller-bugs@googlegroups.com
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On Fri, Nov 24, 2023 at 4:11=E2=80=AFPM Jann Horn <jannh@google.com> wrote:
>
> On Wed, Sep 27, 2023 at 5:10=E2=80=AFPM syzbot
> <syzbot+477d8d8901756d1cbba1@syzkaller.appspotmail.com> wrote:
> > syzbot has tested the proposed patch and the reproducer did not trigger=
 any issue:
> >
> > Reported-and-tested-by: syzbot+477d8d8901756d1cbba1@syzkaller.appspotma=
il.com
> >
> > Tested on:
> >
> > commit:         8e9b46c4 ovl: do not encode lower fh with upper sb_wri.=
.
> > git tree:       https://github.com/amir73il/linux.git ovl_want_write
> > console output: https://syzkaller.appspot.com/x/log.txt?x=3D10d10ffa680=
000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=3Dbb54ecdfa19=
7f132
> > dashboard link: https://syzkaller.appspot.com/bug?extid=3D477d8d8901756=
d1cbba1
> > compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for=
 Debian) 2.40
>
> It looks like the fix was submitted without the Reported-by tag, so
> syzkaller doesn't recognize that the fix has landed... I'll tell
> syzkaller now which commit the fix is supposed to be in, please
> correct me if this is wrong:
>
> #syz fix: ovl: do not encode lower fh with upper sb_writers held

(Ah, and just for the record: I hadn't realized when writing this that
the fix was actually in a newer version of the same patch... "git
range-diff 44ef23e481b02df2f17599a24f81cf0045dc5256~1..44ef23e481b02df2f175=
99a24f81cf0045dc5256
5b02bfc1e7e3811c5bf7f0fa626a0694d0dbbd77~1..5b02bfc1e7e3811c5bf7f0fa626a069=
4d0dbbd77"
shows an added "ovl_get_index_name", I guess that's the fix?)