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From: James Hughes <james.hughes@raspberrypi.org>
To: Arend van Spriel <arend.vanspriel@broadcom.com>,
	Franky Lin <franky.lin@broadcom.com>,
	Hante Meuleman <hante.meuleman@broadcom.com>,
	Kalle Valo <kvalo@codeaurora.org>,
	linux-wireless@vger.kernel.org,
	brcm80211-dev-list.pdl@broadcom.com, netdev@vger.kernel.org
Cc: James Hughes <james.hughes@raspberrypi.org>
Subject: [PATCH] brcmfmac: Ensure pointer correctly set if skb data location changes
Date: Mon, 24 Apr 2017 11:52:19 +0100	[thread overview]
Message-ID: <20170424105219.18797-1-james.hughes@raspberrypi.org> (raw)

The incoming skb header may be resized if header space is
insufficient, which might change the data adddress in the skb.
Ensure that a cached pointer to that data is correctly set by
moving assignment to after any possible changes.

Signed-off-by: James Hughes <james.hughes@raspberrypi.org>
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
index 5eaac13e2317..934fe00e28a0 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
@@ -198,7 +198,7 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb,
 	int ret;
 	struct brcmf_if *ifp = netdev_priv(ndev);
 	struct brcmf_pub *drvr = ifp->drvr;
-	struct ethhdr *eh = (struct ethhdr *)(skb->data);
+	struct ethhdr *eh;
 
 	brcmf_dbg(DATA, "Enter, bsscfgidx=%d\n", ifp->bsscfgidx);
 
@@ -229,6 +229,8 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb,
 		}
 	}
 
+	eh = (struct ethhdr *)(skb->data);
+
 	/* validate length for ether packet */
 	if (skb->len < sizeof(*eh)) {
 		ret = -EINVAL;
-- 
2.11.0

             reply	other threads:[~2017-04-24 10:52 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-04-24 10:52 James Hughes [this message]
2017-04-24 11:10 ` [PATCH] brcmfmac: Ensure pointer correctly set if skb data location changes Arend van Spriel

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