From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ivan Vecera Subject: [PATCH net] tg3: avoid double-freeing of rx data memory Date: Wed, 6 Nov 2013 14:02:36 +0100 Message-ID: <1383742956-18731-1-git-send-email-ivecera@redhat.com> Cc: davem@davemloft.net, Nithin Nayak Sujir , Michael Chan To: netdev@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:31574 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756152Ab3KFNCl (ORCPT ); Wed, 6 Nov 2013 08:02:41 -0500 Sender: netdev-owner@vger.kernel.org List-ID: If build_skb fails the memory associated with the ring buffer is freed but the ri->data member is not zeroed in this case. This causes a double-free of this memory in tg3_free_rings->... path. The patch moves this block after setting ri->data to NULL. It would be nice to fix this bug also in stable >= v3.4 trees. Cc: Nithin Nayak Sujir Cc: Michael Chan Signed-off-by: Ivan Vecera --- drivers/net/ethernet/broadcom/tg3.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c index 12d961c..cd76d2a 100644 --- a/drivers/net/ethernet/broadcom/tg3.c +++ b/drivers/net/ethernet/broadcom/tg3.c @@ -6848,12 +6848,6 @@ static int tg3_rx(struct tg3_napi *tnapi, int budget) pci_unmap_single(tp->pdev, dma_addr, skb_size, PCI_DMA_FROMDEVICE); - skb = build_skb(data, frag_size); - if (!skb) { - tg3_frag_free(frag_size != 0, data); - goto drop_it_no_recycle; - } - skb_reserve(skb, TG3_RX_OFFSET(tp)); /* Ensure that the update to the data happens * after the usage of the old DMA mapping. */ @@ -6861,6 +6855,12 @@ static int tg3_rx(struct tg3_napi *tnapi, int budget) ri->data = NULL; + skb = build_skb(data, frag_size); + if (!skb) { + tg3_frag_free(frag_size != 0, data); + goto drop_it_no_recycle; + } + skb_reserve(skb, TG3_RX_OFFSET(tp)); } else { tg3_recycle_rx(tnapi, tpr, opaque_key, desc_idx, *post_ptr); -- 1.8.1.5