[PATCH stable-3.16 1/2] brcmfmac: Ensure pointer correctly set if skb data location changes

[PATCH stable-3.16 1/2] brcmfmac: Ensure pointer correctly set if skb data location changes

[Arend van Spriel]

From: James Hughes <james.hughes@raspberrypi.org>

commit 455a1eb4654c24560eb9dfc634f29cba3d87601e upstream

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>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
---
This patch should be applied to the linux-3.16.y branch.

Regards,
Arend
---
 drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c b/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c
index 09dd8c1..2b563de 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c
@@ -190,7 +190,7 @@ 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, idx=%d\n", ifp->bssidx);
 
@@ -236,6 +236,8 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb,
 		goto done;
 	}
 
+	eh = (struct ethhdr *)(skb->data);
+
 	if (eh->h_proto == htons(ETH_P_PAE))
 		atomic_inc(&ifp->pend_8021x_cnt);
 
-- 
1.9.1

[PATCH stable-3.16 2/2] brcmfmac: Make skb header writable before use

[Arend van Spriel]

From: James Hughes <james.hughes@raspberrypi.org>

commit 9cc4b7cb86cbcc6330a3faa8cd65268cd2d3c227 upstream

The driver was making changes to the skb_header without
ensuring it was writable (i.e. uncloned).
This patch also removes some boiler plate header size
checking/adjustment code as that is also handled by the
skb_cow_header function used to make header writable.

Signed-off-by: James Hughes <james.hughes@raspberrypi.org>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
---
This patch should be applied to the linux-3.16 branch.

Regards,
Arend
---
 drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c | 19 +++++--------------
 1 file changed, 5 insertions(+), 14 deletions(-)

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c b/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c
index 2b563de..ef8baea 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/dhd_linux.c
@@ -211,22 +211,13 @@ static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb,
 		goto done;
 	}
 
-	/* Make sure there's enough room for any header */
-	if (skb_headroom(skb) < drvr->hdrlen) {
-		struct sk_buff *skb2;
-
-		brcmf_dbg(INFO, "%s: insufficient headroom\n",
+	/* Make sure there's enough writable headroom*/
+	ret = skb_cow_head(skb, drvr->hdrlen);
+	if (ret < 0) {
+		brcmf_err("%s: skb_cow_head failed\n",
 			  brcmf_ifname(drvr, ifp->bssidx));
-		drvr->bus_if->tx_realloc++;
-		skb2 = skb_realloc_headroom(skb, drvr->hdrlen);
 		dev_kfree_skb(skb);
-		skb = skb2;
-		if (skb == NULL) {
-			brcmf_err("%s: skb_realloc_headroom failed\n",
-				  brcmf_ifname(drvr, ifp->bssidx));
-			ret = -ENOMEM;
-			goto done;
-		}
+		goto done;
 	}
 
 	/* validate length for ether packet */
-- 
1.9.1