Re: [HPDD-discuss] [PATCH] staging: lustre: include: lustre_update.h: Fix for possible null pointer dereference

[Frank Zago]

On 01/29/2015 01:47 PM, Rickard Strandqvist wrote:
> 2015-01-29 20:40 GMT+01:00 Frank Zago <fzago@xxxxxxxx>:
> > On 01/29/2015 12:47 PM, Rickard Strandqvist wrote:
> > > Fix a possible null pointer dereference, there is
> > > otherwise a risk of a possible null pointer dereference.
> > >
> > > This was found using a static code analysis program called cppcheck
> > >
> > > Signed-off-by: Rickard Strandqvist
> > > <rickard_strandqvist@xxxxxxxxxxxxxxxxxx>
> > > ---
> > >    drivers/staging/lustre/lustre/include/lustre_update.h |    4 +++-
> > >    1 file changed, 3 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/staging/lustre/lustre/include/lustre_update.h
> > > b/drivers/staging/lustre/lustre/include/lustre_update.h
> > > index 84defce..00e1361 100644
> > > --- a/drivers/staging/lustre/lustre/include/lustre_update.h
> > > +++ b/drivers/staging/lustre/lustre/include/lustre_update.h
> > > @@ -165,12 +165,14 @@ static inline int update_get_reply_buf(struct
> > > update_reply *reply, void **buf,
> > >          int  result;
> > >
> > >          ptr = update_get_buf_internal(reply, index, &size);
> > > +
> > > +       LASSERT((ptr != NULL && size >= sizeof(int)));
> >
> >
> > Now size is tested before result. So it could assert if result < 0, while
> > the function would have returned before.
> >
> >
> > > +
> > >          result = *(int *)ptr;
> > >
> > >          if (result < 0)
> > >                  return result;
> > >
> > > -       LASSERT((ptr != NULL && size >= sizeof(int)));
> > >          *buf = ptr + sizeof(int);
> > >          return size - sizeof(int);
> > >    }
>
>
>
> But if prt is null krachar on the line:
> result = *(int *)ptr;
>
> Maybe there should be two LASSERT then.


Yes, that would be safer.

Frank.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/