Re: [GIT PULL] Fix for Integrity subsystem null pointer deref

From: Mimi Zohar
Date: Wed Oct 29 2014 - 16:20:33 EST


On Wed, 2014-10-29 at 11:51 -0700, Andy Lutomirski wrote:
> On Wed, Oct 29, 2014 at 11:36 AM, Dan Carpenter
> <dan.carpenter@xxxxxxxxxx> wrote:
> > On Wed, Oct 29, 2014 at 09:23:45AM -0700, Andy Lutomirski wrote:
> >> I have no idea what the semantics are. All I'm saying is that it
> >> looks like the code still accesses memory past the end of the buffer.
> >> The buffer isn't a null pointer, so the symptom is different, but it
> >> may still be a security bug.
> >>
> >> --Andy
> >
> > It only reads one byte into the struct "xattr_data->type" so checking
> > for non-zero is sufficient and the patch is fine.
>
> Indeed. Still... eww. I don't like code that, upon local inspection,
> is apparently wrong, even though it's coincidentally correct due to
> some other far away condition.

No, the code may be incomplete, but definitely not wrong.

Mimi

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