From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from youngberry.canonical.com ([91.189.89.112]:48556 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752123AbbH0WMb (ORCPT ); Thu, 27 Aug 2015 18:12:31 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Simon Guinot , "David S. Miller" , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 025/130] net: mvneta: fix refilling for Rx DMA buffers Date: Thu, 27 Aug 2015 15:10:16 -0700 Message-Id: <1440713521-5906-26-git-send-email-kamal@canonical.com> In-Reply-To: <1440713521-5906-1-git-send-email-kamal@canonical.com> References: <1440713521-5906-1-git-send-email-kamal@canonical.com> Sender: stable-owner@vger.kernel.org List-ID: 3.19.8-ckt6 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Simon Guinot commit a84e32894191cfcbffa54180d78d7d4654d56c20 upstream. With the actual code, if a memory allocation error happens while refilling a Rx descriptor, then the original Rx buffer is both passed to the networking stack (in a SKB) and let in the Rx ring. This leads to various kernel oops and crashes. As a fix, this patch moves Rx descriptor refilling ahead of building SKB with the associated Rx buffer. In case of a memory allocation failure, data is dropped and the original DMA buffer is put back into the Rx ring. Signed-off-by: Simon Guinot Fixes: c5aff18204da ("net: mvneta: driver for Marvell Armada 370/XP network unit") Tested-by: Yoann Sculo Signed-off-by: David S. Miller Signed-off-by: Kamal Mostafa --- drivers/net/ethernet/marvell/mvneta.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index 2562249..fab4757 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -1435,7 +1435,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, struct mvneta_rx_queue *rxq) { struct net_device *dev = pp->dev; - int rx_done, rx_filled; + int rx_done; u32 rcvd_pkts = 0; u32 rcvd_bytes = 0; @@ -1446,7 +1446,6 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, rx_todo = rx_done; rx_done = 0; - rx_filled = 0; /* Fairness NAPI loop */ while (rx_done < rx_todo) { @@ -1457,7 +1456,6 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, int rx_bytes, err; rx_done++; - rx_filled++; rx_status = rx_desc->status; rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE); data = (unsigned char *)rx_desc->buf_cookie; @@ -1497,6 +1495,14 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, continue; } + /* Refill processing */ + err = mvneta_rx_refill(pp, rx_desc); + if (err) { + netdev_err(dev, "Linux processing - Can't refill\n"); + rxq->missed++; + goto err_drop_frame; + } + skb = build_skb(data, pp->frag_size > PAGE_SIZE ? 0 : pp->frag_size); if (!skb) goto err_drop_frame; @@ -1516,14 +1522,6 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, mvneta_rx_csum(pp, rx_status, skb); napi_gro_receive(&pp->napi, skb); - - /* Refill processing */ - err = mvneta_rx_refill(pp, rx_desc); - if (err) { - netdev_err(dev, "Linux processing - Can't refill\n"); - rxq->missed++; - rx_filled--; - } } if (rcvd_pkts) { @@ -1536,7 +1534,7 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, } /* Update rxq management counters */ - mvneta_rxq_desc_num_update(pp, rxq, rx_done, rx_filled); + mvneta_rxq_desc_num_update(pp, rxq, rx_done, rx_done); return rx_done; } -- 1.9.1