Patch "net: mvneta: fix error path for building skb" has been added to the 4.3-stable tree

Patch "net: mvneta: fix error path for building skb" has been added to the 4.3-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    net: mvneta: fix error path for building skb

to the 4.3-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:
     net-mvneta-fix-error-path-for-building-skb.patch
and it can be found in the queue-4.3 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 26c17a179f3f64f92de6e837c14279a6431a7ab6 Mon Sep 17 00:00:00 2001
From: Marcin Wojtas <mw@semihalf.com>
Date: Mon, 30 Nov 2015 13:27:44 +0100
Subject: net: mvneta: fix error path for building skb

From: Marcin Wojtas <mw@semihalf.com>

commit 26c17a179f3f64f92de6e837c14279a6431a7ab6 upstream.

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 <mw@semihalf.com>
Acked-by: Simon Guinot <simon.guinot@sequanux.org>
Fixes a84e32894191 ("net: mvneta: fix refilling for Rx DMA buffers")
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/net/ethernet/marvell/mvneta.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -1533,12 +1533,16 @@ static int mvneta_rx(struct mvneta_port
 		}
 
 		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;
 


Patches currently in stable-queue which might be from mw@semihalf.com are

queue-4.3/net-mvneta-fix-error-path-for-building-skb.patch