From 26c17a179f3f64f92de6e837c14279a6431a7ab6 Mon Sep 17 00:00:00 2001 From: Marcin Wojtas Date: Mon, 30 Nov 2015 13:27:44 +0100 Subject: [PATCH] net: mvneta: fix error path for building skb In the actual RX processing, there is same error path for both descriptor ring refilling and building skb fails. This is not correct, because after successful refill, the ring is already updated with newly allocated buffer. Then, in case of build_skb() fail, hitherto code left the original buffer unmapped. This patch fixes above situation by swapping error check of skb build with DMA-unmap of original buffer. Signed-off-by: Marcin Wojtas Acked-by: Simon Guinot Cc: # v4.2+ Fixes a84e32894191 ("net: mvneta: fix refilling for Rx DMA buffers") Signed-off-by: David S. Miller --- drivers/net/ethernet/marvell/mvneta.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index 5dffb6831236..5a98c5d61a2b 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -1580,12 +1580,16 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo, } skb = build_skb(data, pp->frag_size > PAGE_SIZE ? 0 : pp->frag_size); - if (!skb) - goto err_drop_frame; + /* After refill old buffer has to be unmapped regardless + * the skb is successfully built or not. + */ dma_unmap_single(dev->dev.parent, phys_addr, MVNETA_RX_BUF_SIZE(pp->pkt_size), DMA_FROM_DEVICE); + if (!skb) + goto err_drop_frame; + rcvd_pkts++; rcvd_bytes += rx_bytes;