From 940e798c818860c5952ac8014fa930e670517f73 Mon Sep 17 00:00:00 2001 From: Andy Spencer Date: Thu, 22 Feb 2018 11:05:33 -0800 Subject: [PATCH] gianfar: simplify FCS handling and fix memory leak commit d903ec77118c09f93a610b384d83a6df33a64fe6 upstream. Previously, buffer descriptors containing only the frame check sequence (FCS) were skipped and not added to the skb. However, the page reference count was still incremented, leading to a memory leak. Fixing this inside gfar_add_rx_frag() is difficult due to reserved memory handling and page reuse. Instead, move the FCS handling to gfar_process_frame() and trim off the FCS before passing the skb up the networking stack. Signed-off-by: Andy Spencer Signed-off-by: Jim Gruen Signed-off-by: David S. Miller Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/freescale/gianfar.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/drivers/net/ethernet/freescale/gianfar.c b/drivers/net/ethernet/freescale/gianfar.c index 9fd68cfdd973..a4346d2580e2 100644 --- a/drivers/net/ethernet/freescale/gianfar.c +++ b/drivers/net/ethernet/freescale/gianfar.c @@ -2939,29 +2939,17 @@ static bool gfar_add_rx_frag(struct gfar_rx_buff *rxb, u32 lstatus, { int size = lstatus & BD_LENGTH_MASK; struct page *page = rxb->page; - bool last = !!(lstatus & BD_LFLAG(RXBD_LAST)); - - /* Remove the FCS from the packet length */ - if (last) - size -= ETH_FCS_LEN; if (likely(first)) { skb_put(skb, size); } else { /* the last fragments' length contains the full frame length */ - if (last) + if (lstatus & BD_LFLAG(RXBD_LAST)) size -= skb->len; - /* Add the last fragment if it contains something other than - * the FCS, otherwise drop it and trim off any part of the FCS - * that was already received. - */ - if (size > 0) - skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, - rxb->page_offset + RXBUF_ALIGNMENT, - size, GFAR_RXB_TRUESIZE); - else if (size < 0) - pskb_trim(skb, skb->len + size); + skb_add_rx_frag(skb, skb_shinfo(skb)->nr_frags, page, + rxb->page_offset + RXBUF_ALIGNMENT, + size, GFAR_RXB_TRUESIZE); } /* try reuse page */ @@ -3074,6 +3062,9 @@ static void gfar_process_frame(struct net_device *ndev, struct sk_buff *skb) if (priv->padding) skb_pull(skb, priv->padding); + /* Trim off the FCS */ + pskb_trim(skb, skb->len - ETH_FCS_LEN); + if (ndev->features & NETIF_F_RXCSUM) gfar_rx_checksum(skb, fcb);