This is a note to let you know that I've just added the patch titled
gianfar: simplify FCS handling and fix memory leak
to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
gianfar-simplify-fcs-handling-and-fix-memory-leak.patch
and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d903ec77118c09f93a610b384d83a6df33a64fe6 Mon Sep 17 00:00:00 2001
From: Andy Spencer <aspencer@xxxxxxxxxx>
Date: Thu, 22 Feb 2018 11:05:33 -0800
Subject: gianfar: simplify FCS handling and fix memory leak
From: Andy Spencer <aspencer@xxxxxxxxxx>
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 <aspencer@xxxxxxxxxx>
Signed-off-by: Jim Gruen <jgruen@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/freescale/gianfar.c | 23 +++++++----------------
1 file changed, 7 insertions(+), 16 deletions(-)
--- 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
{
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 ne
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);
Patches currently in stable-queue which might be from aspencer@xxxxxxxxxx are
queue-4.9/gianfar-simplify-fcs-handling-and-fix-memory-leak.patch
