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* net/9p/mux.c: use-after-free
@ 2007-07-23  1:20 Adrian Bunk
  2007-07-25 18:43 ` Eric Van Hensbergen
  0 siblings, 1 reply; 4+ messages in thread
From: Adrian Bunk @ 2007-07-23  1:20 UTC (permalink / raw)
  To: Latchesar Ionkov, Eric Van Hensbergen
  Cc: v9fs-developer, netdev, linux-kernel

The Coverity checker spotted the following use-after-free
in net/9p/mux.c:

<--  snip  -->

...
struct p9_conn *p9_conn_create(struct p9_transport *trans, int msize,
                                    unsigned char *extended)
{
...
        if (!m->tagpool) {
                kfree(m);
                return ERR_PTR(PTR_ERR(m->tagpool));
        }
...

<--  snip  -->


cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed


^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: net/9p/mux.c: use-after-free
  2007-07-23  1:20 net/9p/mux.c: use-after-free Adrian Bunk
@ 2007-07-25 18:43 ` Eric Van Hensbergen
  2007-07-25 19:13   ` Latchesar Ionkov
  0 siblings, 1 reply; 4+ messages in thread
From: Eric Van Hensbergen @ 2007-07-25 18:43 UTC (permalink / raw)
  To: Adrian Bunk; +Cc: Latchesar Ionkov, v9fs-developer, netdev, linux-kernel

On 7/22/07, Adrian Bunk <bunk@stusta.de> wrote:
> The Coverity checker spotted the following use-after-free
> in net/9p/mux.c:
>
> <--  snip  -->
>
> ...
> struct p9_conn *p9_conn_create(struct p9_transport *trans, int msize,
>                                     unsigned char *extended)
> {
> ...
>         if (!m->tagpool) {
>                 kfree(m);
>                 return ERR_PTR(PTR_ERR(m->tagpool));
>         }
> ...
>
> <--  snip  -->
>

I've got a fix for this one:
        if (!m->tagpool) {
                mtmp = ERR_PTR(PTR_ERR(m->tagpool));
                kfree(m);
                return mtmp;
        }

but I was wondering about one of the other returns further down the function:

...
        memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
        m->poll_task = NULL;
        n = p9_mux_poll_start(m);
        if (n)
                return ERR_PTR(n);

        n = trans->poll(trans, &m->pt);
...

lucho: doesn't that constitute a leak?  Shouldn't we be doing:

        if (n) {
                kfree(m);
                return ERR_PTR(n);
        }

         -eric

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: net/9p/mux.c: use-after-free
  2007-07-25 18:43 ` Eric Van Hensbergen
@ 2007-07-25 19:13   ` Latchesar Ionkov
  2007-07-25 19:45     ` Eric Van Hensbergen
  0 siblings, 1 reply; 4+ messages in thread
From: Latchesar Ionkov @ 2007-07-25 19:13 UTC (permalink / raw)
  To: Eric Van Hensbergen; +Cc: Adrian Bunk, v9fs-developer, netdev, linux-kernel

Yep, it's a leak.

Thanks,
    Lucho

On 7/25/07, Eric Van Hensbergen <ericvh@gmail.com> wrote:
> On 7/22/07, Adrian Bunk <bunk@stusta.de> wrote:
> > The Coverity checker spotted the following use-after-free
> > in net/9p/mux.c:
> >
> > <--  snip  -->
> >
> > ...
> > struct p9_conn *p9_conn_create(struct p9_transport *trans, int msize,
> >                                     unsigned char *extended)
> > {
> > ...
> >         if (!m->tagpool) {
> >                 kfree(m);
> >                 return ERR_PTR(PTR_ERR(m->tagpool));
> >         }
> > ...
> >
> > <--  snip  -->
> >
>
> I've got a fix for this one:
>         if (!m->tagpool) {
>                 mtmp = ERR_PTR(PTR_ERR(m->tagpool));
>                 kfree(m);
>                 return mtmp;
>         }
>
> but I was wondering about one of the other returns further down the function:
>
> ...
>         memset(&m->poll_waddr, 0, sizeof(m->poll_waddr));
>         m->poll_task = NULL;
>         n = p9_mux_poll_start(m);
>         if (n)
>                 return ERR_PTR(n);
>
>         n = trans->poll(trans, &m->pt);
> ...
>
> lucho: doesn't that constitute a leak?  Shouldn't we be doing:
>
>         if (n) {
>                 kfree(m);
>                 return ERR_PTR(n);
>         }
>
>          -eric
>

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: net/9p/mux.c: use-after-free
  2007-07-25 19:13   ` Latchesar Ionkov
@ 2007-07-25 19:45     ` Eric Van Hensbergen
  0 siblings, 0 replies; 4+ messages in thread
From: Eric Van Hensbergen @ 2007-07-25 19:45 UTC (permalink / raw)
  To: Latchesar Ionkov; +Cc: Adrian Bunk, v9fs-developer, netdev, linux-kernel

On 7/25/07, Latchesar Ionkov <lucho@ionkov.net> wrote:
> Yep, it's a leak.
>

Okay, I'll roll that into the patch as well.

           -eric

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2007-07-25 19:45 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2007-07-23  1:20 net/9p/mux.c: use-after-free Adrian Bunk
2007-07-25 18:43 ` Eric Van Hensbergen
2007-07-25 19:13   ` Latchesar Ionkov
2007-07-25 19:45     ` Eric Van Hensbergen

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