Re: [syzbot] [overlayfs?] KASAN: invalid-free in ovl_copy_up_one

[Jann Horn]

On Fri, Nov 24, 2023 at 4:11 PM Jann Horn <jannh@xxxxxxxxxx> wrote:
>
> On Wed, Sep 27, 2023 at 5:10 PM syzbot
> <syzbot+477d8d8901756d1cbba1@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
> > syzbot has tested the proposed patch and the reproducer did not trigger any issue:
> >
> > Reported-and-tested-by: syzbot+477d8d8901756d1cbba1@xxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > 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=10d10ffa680000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=bb54ecdfa197f132
> > dashboard link: https://syzkaller.appspot.com/bug?extid=477d8d8901756d1cbba1
> > 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the fix was actually in a newer version of the same patch...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..44ef23e481b02df2f17599a24f81cf0045dc5256
5b02bfc1e7e3811c5bf7f0fa626a0694d0dbbd77~1..5b02bfc1e7e3811c5bf7f0fa626a0694d0dbbd77"
shows an added "ovl_get_index_name", I guess that's the fix?)