Patch "net: mvneta: fix DMA buffer unmapping in mvneta_rx()" has been added to the 4.2-stable tree

[<gregkh@linuxfoundation.org>]

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

    net: mvneta: fix DMA buffer unmapping in mvneta_rx()

to the 4.2-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-dma-buffer-unmapping-in-mvneta_rx.patch
and it can be found in the queue-4.2 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 foo@baz Wed Sep 30 05:25:07 CEST 2015
From: Simon Guinot <simon.guinot@sequanux.org>
Date: Tue, 15 Sep 2015 22:41:21 +0200
Subject: net: mvneta: fix DMA buffer unmapping in mvneta_rx()

From: Simon Guinot <simon.guinot@sequanux.org>

[ Upstream commit daf158d0d544cec80b7b30deff8cfc59a6e17610 ]

This patch fixes a regression introduced by the commit a84e32894191
("net: mvneta: fix refilling for Rx DMA buffers"). Due to this commit
the newly allocated Rx buffers are DMA-unmapped in place of those passed
to the networking stack. Obviously, this causes data corruptions.

This patch fixes the issue by ensuring that the right Rx buffers are
DMA-unmapped.

Reported-by: Oren Laskin <oren@igneous.io>
Signed-off-by: Simon Guinot <simon.guinot@sequanux.org>
Fixes: a84e32894191 ("net: mvneta: fix refilling for Rx DMA buffers")
Cc: <stable@vger.kernel.org> # v3.8+
Tested-by: Oren Laskin <oren@igneous.io>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/marvell/mvneta.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -1479,6 +1479,7 @@ static int mvneta_rx(struct mvneta_port
 		struct mvneta_rx_desc *rx_desc = mvneta_rxq_next_desc_get(rxq);
 		struct sk_buff *skb;
 		unsigned char *data;
+		dma_addr_t phys_addr;
 		u32 rx_status;
 		int rx_bytes, err;
 
@@ -1486,6 +1487,7 @@ static int mvneta_rx(struct mvneta_port
 		rx_status = rx_desc->status;
 		rx_bytes = rx_desc->data_size - (ETH_FCS_LEN + MVNETA_MH_SIZE);
 		data = (unsigned char *)rx_desc->buf_cookie;
+		phys_addr = rx_desc->buf_phys_addr;
 
 		if (!mvneta_rxq_desc_is_first_last(rx_status) ||
 		    (rx_status & MVNETA_RXD_ERR_SUMMARY)) {
@@ -1534,7 +1536,7 @@ static int mvneta_rx(struct mvneta_port
 		if (!skb)
 			goto err_drop_frame;
 
-		dma_unmap_single(dev->dev.parent, rx_desc->buf_phys_addr,
+		dma_unmap_single(dev->dev.parent, phys_addr,
 				 MVNETA_RX_BUF_SIZE(pp->pkt_size), DMA_FROM_DEVICE);
 
 		rcvd_pkts++;


Patches currently in stable-queue which might be from simon.guinot@sequanux.org are

queue-4.2/net-mvneta-fix-dma-buffer-unmapping-in-mvneta_rx.patch