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Commit 2670cc69 authored by Marc Zyngier's avatar Marc Zyngier Committed by David S. Miller
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net: sun4i-emac: fix memory leak on bad packet 



Upon reception of a new frame, the emac driver checks for a number
of error conditions, and flag the packet as "bad" if any of these
are present. It then allocates a skb unconditionally, but only uses
it if the packet is "good". On the error path, the skb is just forgotten,
and the system leaks memory.

The piece of junk I have on my desk seems to encounter such error
frequently enough so that the box goes OOM after a couple of days,
which makes me grumpy.

Fix this by moving the allocation on the "good_packet" path (and
convert it to netdev_alloc_skb while we're at it).

Tested on a random Allwinner A20 board.

Cc: Stefan Roese <sr@denx.de>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: <stable@vger.kernel.org> # 3.11+
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Acked-by: default avatarMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 757efd32

drivers/net/ethernet/allwinner/sun4i-emac.c

+4 −2
Original line number Diff line number Diff line
@@ -633,8 +633,10 @@ static void emac_rx(struct net_device *dev) 
		}



		/* Move data from EMAC */

		skb = dev_alloc_skb(rxlen + 4);

		if (good_packet && skb) {

		if (good_packet) {

			skb = netdev_alloc_skb(dev, rxlen + 4);

			if (!skb)

				continue;

			skb_reserve(skb, 2);

			rdptr = (u8 *) skb_put(skb, rxlen - 4);