linux-kernel - [PATCH v2 net 4/6] net: mvneta: fix error path for building skb

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1448561293-16431-5-git-send-email-mw@semihalf.com>
Date:	Thu, 26 Nov 2015 19:08:11 +0100
From:	Marcin Wojtas <mw@...ihalf.com>
To:	linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	netdev@...r.kernel.org
Cc:	davem@...emloft.net, linux@....linux.org.uk,
	sebastian.hesselbarth@...il.com, andrew@...n.ch,
	jason@...edaemon.net, thomas.petazzoni@...e-electrons.com,
	gregory.clement@...e-electrons.com, simon.guinot@...uanux.org,
	nadavh@...vell.com, alior@...vell.com, xswang@...vell.com,
	myair@...vell.com, nitroshift@...oo.com, mw@...ihalf.com,
	jaz@...ihalf.com, tn@...ihalf.com, <stable@...r.kernel.org>
Subject: [PATCH v2 net 4/6] net: mvneta: fix error path for building skb

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@...ihalf.com>
Cc: <stable@...r.kernel.org> # v4.2+
Fixes a84e32894191 ("net: mvneta: fix refilling for Rx DMA buffers")
---
 drivers/net/ethernet/marvell/mvneta.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c
index 0c3d923..62cf971 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -1580,12 +1580,16 @@ static int mvneta_rx(struct mvneta_port *pp, int rx_todo,
 		}
 
 		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;
 
-- 
1.8.3.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/