Re: [PATCH] IB/rxe: check for allocation failure on elem

[Leon Romanovsky]

On Sat, Sep 09, 2017 at 03:56:07PM +0300, Leon Romanovsky wrote:
> On Fri, Sep 08, 2017 at 03:37:45PM +0100, Colin King wrote:
> > From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> >
> > The allocation for elem may fail (especially because we're using
> > GFP_ATOMIC) so best to check for a null return.  This fixes a potential
> > null pointer dereference when assigning elem->pool.
> >
> > Detected by CoverityScan CID#1357507 ("Dereference null return value")
> >
> > Fixes: 8700e3e7c485 ("Soft RoCE driver")
> > Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
> > ---
> >  drivers/infiniband/sw/rxe/rxe_pool.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
> > index c1b5f38f31a5..3b4916680018 100644
> > --- a/drivers/infiniband/sw/rxe/rxe_pool.c
> > +++ b/drivers/infiniband/sw/rxe/rxe_pool.c
> > @@ -404,6 +404,8 @@ void *rxe_alloc(struct rxe_pool *pool)
> >  	elem = kmem_cache_zalloc(pool_cache(pool),
> >  				 (pool->flags & RXE_POOL_ATOMIC) ?
> >  				 GFP_ATOMIC : GFP_KERNEL);
> > +	if (!elem)
> > +		return NULL;
> >
>
> It is not enough to simply return NULL, you also should release "pool" too.

Colin,
do you plan to fix the comment and resend it?

Thanks

>
> Thanks
>
> >  	elem->pool = pool;
> >  	kref_init(&elem->ref_cnt);
> > --
> > 2.14.1
> >

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