On Thu, Jul 26, 2018 at 12:09:50AM +0900, Taehee Yoo wrote:
> rhashtable_lookup() can return NULL. so that NULL pointer
> check routine should be added.
>
> Fixes: 02b55e5657c3 ("xdp: add MEM_TYPE_ZERO_COPY")
> Signed-off-by: Taehee Yoo <ap420...@gmail.com>
Acked-by: Martin KaFai Lau <ka...@fb.com>
> ---
> V2 : add WARN_ON_ONCE when xa is NULL.
>
> net/core/xdp.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/net/core/xdp.c b/net/core/xdp.c
> index 9d1f220..786fdbe 100644
> --- a/net/core/xdp.c
> +++ b/net/core/xdp.c
> @@ -345,7 +345,10 @@ static void __xdp_return(void *data, struct xdp_mem_info
> *mem, bool napi_direct,
> rcu_read_lock();
> /* mem->id is valid, checked in xdp_rxq_info_reg_mem_model() */
> xa = rhashtable_lookup(mem_id_ht, &mem->id, mem_id_rht_params);
> - xa->zc_alloc->free(xa->zc_alloc, handle);
> + if (!xa)
> + WARN_ON_ONCE(1);
> + else
> + xa->zc_alloc->free(xa->zc_alloc, handle);
> rcu_read_unlock();
> default:
> /* Not possible, checked in xdp_rxq_info_reg_mem_model() */
> --
> 2.9.3
>
