From c10e4cafa2698dedb9b61bbf6d68f209e779cb19 Mon Sep 17 00:00:00 2001 From: Iyappan Subramanian Date: Thu, 21 Aug 2014 13:44:48 -0700 Subject: net: xgene: fix possible NULL dereference in xgene_enet_free_desc_rings() A NULL pointer dereference is possible for the argument ring->buf_pool which is passed to xgene_enet_free_desc_ring(), as ring could be NULL. And now since NULL pointers are being checked for before the calls to xgene_enet_free_desc_ring(), might as well take advantage of them and not call the function if the argument would be NULL. Reported-by: Dan Carpenter Signed-off-by: Iyappan Subramanian Signed-off-by: David S. Miller --- drivers/net/ethernet/apm/xgene/xgene_enet_main.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c index e1a8f4e19983..e4222af2baa6 100644 --- a/drivers/net/ethernet/apm/xgene/xgene_enet_main.c +++ b/drivers/net/ethernet/apm/xgene/xgene_enet_main.c @@ -563,15 +563,21 @@ static void xgene_enet_free_desc_rings(struct xgene_enet_pdata *pdata) struct xgene_enet_desc_ring *ring; ring = pdata->tx_ring; - if (ring && ring->cp_ring && ring->cp_ring->cp_skb) - devm_kfree(dev, ring->cp_ring->cp_skb); - xgene_enet_free_desc_ring(ring); + if (ring) { + if (ring->cp_ring && ring->cp_ring->cp_skb) + devm_kfree(dev, ring->cp_ring->cp_skb); + xgene_enet_free_desc_ring(ring); + } ring = pdata->rx_ring; - if (ring && ring->buf_pool && ring->buf_pool->rx_skb) - devm_kfree(dev, ring->buf_pool->rx_skb); - xgene_enet_free_desc_ring(ring->buf_pool); - xgene_enet_free_desc_ring(ring); + if (ring) { + if (ring->buf_pool) { + if (ring->buf_pool->rx_skb) + devm_kfree(dev, ring->buf_pool->rx_skb); + xgene_enet_free_desc_ring(ring->buf_pool); + } + xgene_enet_free_desc_ring(ring); + } } static struct xgene_enet_desc_ring *xgene_enet_create_desc_ring( -- cgit v1.2.3