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From:   Aleksander Jan Bajkowski <olek2@wp.pl>
To:     hauke@hauke-m.de, davem@davemloft.net, edumazet@google.com,
        kuba@kernel.org, pabeni@redhat.com, olek2@wp.pl,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH net v3 3/3] net: lantiq_xrx200: restore buffer if memory allocation failed
Date:   Wed, 24 Aug 2022 23:54:08 +0200
Message-Id: <20220824215408.4695-4-olek2@wp.pl>
In-Reply-To: <20220824215408.4695-1-olek2@wp.pl>
References: <20220824215408.4695-1-olek2@wp.pl>
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Precedence: bulk

In a situation where memory allocation fails, an invalid buffer address
is stored. When this descriptor is used again, the system panics in the
build_skb() function when accessing memory.

Fixes: 7ea6cd16f159 ("lantiq: net: fix duplicated skb in rx descriptor ring")
Signed-off-by: Aleksander Jan Bajkowski <olek2@wp.pl>
---
 drivers/net/ethernet/lantiq_xrx200.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/lantiq_xrx200.c b/drivers/net/ethernet/lantiq_xrx200.c
index 25adce7f0c7c..57f27cc7724e 100644
--- a/drivers/net/ethernet/lantiq_xrx200.c
+++ b/drivers/net/ethernet/lantiq_xrx200.c
@@ -193,6 +193,7 @@ static int xrx200_alloc_buf(struct xrx200_chan *ch, void *(*alloc)(unsigned int
 
 	ch->rx_buff[ch->dma.desc] = alloc(priv->rx_skb_size);
 	if (!ch->rx_buff[ch->dma.desc]) {
+		ch->rx_buff[ch->dma.desc] = buf;
 		ret = -ENOMEM;
 		goto skip;
 	}
-- 
2.30.2