diff mbox

IB/rxe: check for allocation failure on elem

Message ID 20170908143745.2445-1-colin.king@canonical.com (mailing list archive)
State Changes Requested
Headers show

Commit Message

Colin King Sept. 8, 2017, 2:37 p.m. UTC
From: Colin Ian King <colin.king@canonical.com>

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@canonical.com>
---
 drivers/infiniband/sw/rxe/rxe_pool.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Leon Romanovsky Sept. 9, 2017, 12:56 p.m. UTC | #1
On Fri, Sep 08, 2017 at 03:37:45PM +0100, Colin King wrote:
> From: Colin Ian King <colin.king@canonical.com>
>
> 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@canonical.com>
> ---
>  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.

Thanks

>  	elem->pool = pool;
>  	kref_init(&elem->ref_cnt);
> --
> 2.14.1
>
Leon Romanovsky Sept. 12, 2017, 2:48 p.m. UTC | #2
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@canonical.com>
> >
> > 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@canonical.com>
> > ---
> >  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
> >
diff mbox

Patch

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