[libvirt] [PATCH] virsh: avoid double-free

[Daniel P. Berrange]

On Mon, Dec 14, 2009 at 04:04:29PM +0100, Daniel Veillard wrote:
> On Mon, Dec 14, 2009 at 02:35:25PM +0100, Jim Meyering wrote:
> > I didn't try to trigger the double free, but it looks feasible.
> > 
> > >From 864cc161ffaf6c08cb980e66a673b53ac5ea52ab Mon Sep 17 00:00:00 2001
> > From: Jim Meyering <meyering at redhat.com>
> > Date: Mon, 14 Dec 2009 14:34:29 +0100
> > Subject: [PATCH] virsh: avoid double-free
> > 
> > * tools/virsh.c (vshCommandParse): Avoid double-free of "tkdata".
> > Set it to NULL immediately after free in the (cmd == NULL) case,
> > just as in the other case, in case the final free(tkdata) is
> > triggered by a syntax error.
> > ---
> >  tools/virsh.c |    1 +
> >  1 files changed, 1 insertions(+), 0 deletions(-)
> > 
> > diff --git a/tools/virsh.c b/tools/virsh.c
> > index 62c1270..0312945 100644
> > --- a/tools/virsh.c
> > +++ b/tools/virsh.c
> > @@ -8044,6 +8044,7 @@ vshCommandParse(vshControl *ctl, char *cmdstr)
> >                      goto syntaxError;   /* ... or ignore this command only? */
> >                  }
> >                  free(tkdata);
> > +                tkdata = NULL;
> >              } else if (tk == VSH_TK_OPTION) {
> >                  if (!(opt = vshCmddefGetOption(cmd, tkdata))) {
> >                      vshError(ctl,
> 
>   ACK, that's the kind of things VIR_FREE() solved, but unfortunately
> it's not available for virsh.c ...

ACK, we could actually use VIR_FREE/etc  in virsh these days.

Daniel
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