From a84e32894191cfcbffa54180d78d7d4654d56c20 Mon Sep 17 00:00:00 2001 From: Simon Guinot Date: Sun, 19 Jul 2015 13:00:53 +0200 Subject: [PATCH] net: mvneta: fix refilling for Rx DMA buffers 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") Cc: # v3.8+ Tested-by: Yoann Sculo Signed-off-by: David S. Miller --- 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 370e20ed224c..62e48bc0cb23 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -1462,7 +1462,7 @@ 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; @@ -1473,7 +1473,6 @@ 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) { @@ -1484,7 +1483,6 @@ 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; @@ -1524,6 +1522,14 @@ 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; @@ -1543,14 +1549,6 @@ 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) { @@ -1563,7 +1561,7 @@ 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; }