2020-09-02 15:17:37

by Björn Töpel

Subject: Re: [PATCH][next] xsk: Fix null check on error return path

On 2020-09-02 17:07, Gustavo A. R. Silva wrote:
> Currently, dma_map is being checked, when the right object identifier
> to be null-checked is dma_map->dma_pages, instead.
>
> Fix this by null-checking dma_map->dma_pages.
>
> Addresses-Coverity-ID: 1496811 ("Logically dead code")
> Fixes: 921b68692abb ("xsk: Enable sharing of dma mappings")
> Signed-off-by: Gustavo A. R. Silva <[email protected]>

Nice catch!

Acked-by: Björn Töpel <[email protected]>

> ---
> net/xdp/xsk_buff_pool.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
> index 795d7c81c0ca..5b00bc5707f2 100644
> --- a/net/xdp/xsk_buff_pool.c
> +++ b/net/xdp/xsk_buff_pool.c
> @@ -287,7 +287,7 @@ static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_devi
> return NULL;
>
> dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
> - if (!dma_map) {
> + if (!dma_map->dma_pages) {
> kfree(dma_map);
> return NULL;
> }
>

2020-09-02 16:24:02

by Gustavo A. R. Silva

Subject: Re: [PATCH][next] xsk: Fix null check on error return path

On Wed, Sep 02, 2020 at 05:12:51PM +0200, Bj?rn T?pel wrote:
> On 2020-09-02 17:07, Gustavo A. R. Silva wrote:
> > Currently, dma_map is being checked, when the right object identifier
> > to be null-checked is dma_map->dma_pages, instead.
> >
> > Fix this by null-checking dma_map->dma_pages.
> >
> > Addresses-Coverity-ID: 1496811 ("Logically dead code")
> > Fixes: 921b68692abb ("xsk: Enable sharing of dma mappings")
> > Signed-off-by: Gustavo A. R. Silva <[email protected]>
>
> Nice catch!
>
> Acked-by: Bj?rn T?pel <[email protected]>
>

Thanks, Bj?rn.

--
Gustavo

> > ---
> > net/xdp/xsk_buff_pool.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/net/xdp/xsk_buff_pool.c b/net/xdp/xsk_buff_pool.c
> > index 795d7c81c0ca..5b00bc5707f2 100644
> > --- a/net/xdp/xsk_buff_pool.c
> > +++ b/net/xdp/xsk_buff_pool.c
> > @@ -287,7 +287,7 @@ static struct xsk_dma_map *xp_create_dma_map(struct device *dev, struct net_devi
> > return NULL;
> > dma_map->dma_pages = kvcalloc(nr_pages, sizeof(*dma_map->dma_pages), GFP_KERNEL);
> > - if (!dma_map) {
> > + if (!dma_map->dma_pages) {
> > kfree(dma_map);
> > return NULL;
> > }
> >