From: Aleksander Jan Bajkowski <olek2@wp.pl>
To: hauke@hauke-m.de, davem@davemloft.net, kuba@kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: Aleksander Jan Bajkowski <olek2@wp.pl>
Subject: [PATCH net] lantiq: net: fix duplicated skb in rx descriptor ring
Date: Sun, 6 Jun 2021 22:05:51 +0200 [thread overview]
Message-ID: <20210606200551.1609521-1-olek2@wp.pl> (raw)
The previous commit didn't fix the bug properly. By mistake, it replaces
the pointer of the next skb in the descriptor ring instead of the current
one. As a result, the two descriptors are assigned the same SKB. The error
is seen during the iperf test when skb_put tries to insert a second packet
and exceeds the available buffer.
Fixes: c7718ee96dbc ("net: lantiq: fix memory corruption in RX ring ")
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
---
drivers/net/ethernet/lantiq_xrx200.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c
index 36dc3e5f6218..e710f83b3700 100644
--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -193,17 +193,18 @@ static int xrx200_hw_receive(struct xrx200_chan *ch)
int ret;
ret = xrx200_alloc_skb(ch);
-
- ch->dma.desc++;
- ch->dma.desc %= LTQ_DESC_NUM;
-
if (ret) {
ch->skb[ch->dma.desc] = skb;
net_dev->stats.rx_dropped++;
+ ch->dma.desc++;
+ ch->dma.desc %= LTQ_DESC_NUM;
netdev_err(net_dev, "failed to allocate new rx buffer\n");
return ret;
}
+ ch->dma.desc++;
+ ch->dma.desc %= LTQ_DESC_NUM;
+
skb_put(skb, len);
skb->protocol = eth_type_trans(skb, net_dev);
netif_receive_skb(skb);
--
2.30.2
next reply other threads:[~2021-06-06 20:07 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-06 20:05 Aleksander Jan Bajkowski [this message]
2021-06-06 22:25 ` [PATCH net] lantiq: net: fix duplicated skb in rx descriptor ring Hauke Mehrtens
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