Re: [PATCH v1] security/apparmor: remove duplicate unpacking in unpack_perm function

[John Johansen]

On 9/10/24 13:57, Serge E. Hallyn wrote:
> On Mon, Sep 09, 2024 at 11:57:05PM -0700, John Johansen wrote:
> > On 8/21/24 00:22, Shen Lichuan wrote:
> > > The code was unpacking the 'allow' parameter twice.
> > > This change removes the duplicate part.
> > >
> > > Signed-off-by: Shen Lichuan <shenlichuan@xxxxxxxx>
> >
> > NAK, this would break the unpack. The first entry is actually a reserved
> > value and is just being thrown away atm. Instead of double unpacking to
> > perms->allow we could unpack it to a temp variable that just gets discarded
>
> Heh, I recon this should probably be documented in a comment? :)

yes, definitely.

> > > ---
> > >    security/apparmor/policy_unpack.c | 1 -
> > >    1 file changed, 1 deletion(-)
> > >
> > > diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
> > > index 5a570235427d..4ec1e1251012 100644
> > > --- a/security/apparmor/policy_unpack.c
> > > +++ b/security/apparmor/policy_unpack.c
> > > @@ -649,7 +649,6 @@ static bool unpack_perm(struct aa_ext *e, u32 version, struct aa_perms *perm)
> > >    		return false;
> > >    	return	aa_unpack_u32(e, &perm->allow, NULL) &&
> > > -		aa_unpack_u32(e, &perm->allow, NULL) &&
> > >    		aa_unpack_u32(e, &perm->deny, NULL) &&
> > >    		aa_unpack_u32(e, &perm->subtree, NULL) &&
> > >    		aa_unpack_u32(e, &perm->cond, NULL) &&