Re: [PATCH v3] [GSOC] ref-filter: fix read invalid union member bug

>
> "ZheNing Hu via GitGitGadget" <gitgitgadget@gmail.com> writes:
>
> > From: ZheNing Hu <adlternative@gmail.com>
> >
> > used_atom.u is an union, and it has different members depending on
> > what atom the auxiliary data the union part of the "struct
> > used_atom" wants to record. At most only one of the members can be
> > valid at any one time. Since the code checks u.remote_ref without
> > even making sure if the atom is "push" or "push:" (which are only
> > two cases that u.remote_ref.push becomes valid), but u.remote_ref
> > shares the same storage for other members of the union, the check
> > was reading from an invalid member, which was the bug.
> >
> > Modify the condition here to check whether the atom name
> > equals to "push" or starts with "push:", to avoid reading the
> > value of invalid member of the union.
> >
> > Helped-by: Junio C Hamano <gitster@pobox.com>
> > Signed-off-by: ZheNing Hu <adlternative@gmail.com>
> > ---
> >     [GSOC] ref-filter: fix read invalid union member bug
> >
> >     Change from last version:
> >     Modify the processing method of the condition: check whether the name of
> >     the atom equals to "push" or starts with "pushs", which can enhanced
> >     security, although it may bring string match overhead.
>
> I do not think this would have much security implication either
> way.  What it buys us is the future-proofing.
>