[PATCH] Avoid overlapping addresses to stpcpy calls in nscd (BZ #16760)

Siddhesh Poyarekar siddhesh@redhat.com
Thu Apr 10 00:13:00 GMT 2014


On Wed, Apr 09, 2014 at 08:22:29PM +0200, Ondřej Bílka wrote:
> On Fri, Mar 28, 2014 at 07:43:22AM +0530, Siddhesh Poyarekar wrote:
> > On Thu, Mar 27, 2014 at 08:22:54PM +0100, Ondřej Bílka wrote:
> > > > > Fix this by using memmove instead of stpcpy.  Tested x86_64 using
> > > > > various combinations of triplets (including NULL and non-NULL ones) to
> > > > > verify that this works correctly and there are no regressions.
> > > >
> > > This could work only with additional assertion that we do not move host
> > > forward otherwise it could overwrite user.
> > 
> > If the host, user and domain are out of order, they are copied in
> > order into a separate area in the buffer before the memmove.  If you
> > think there's something else that could move host forward then I don't
> > understand and you'll have to elaborate a bit.
> > 
> > Siddhesh
> 
> They are in order, its best to show on example what I mean by copying:
> 
> host  user  domain
>    ^

OK, now I see what you mean by 'moving host forward'.  We don't do
that.

Siddhesh

> hoshostser  domain
> 
> hoshost tserdomain
> 
> hoshost tser domain
> 
> 
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