Patch "lan78xx: use skb_cow_head() to deal with cloned skbs" has been added to the 4.9-stable tree

Patch "lan78xx: use skb_cow_head() to deal with cloned skbs" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    lan78xx: use skb_cow_head() to deal with cloned skbs

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     lan78xx-use-skb_cow_head-to-deal-with-cloned-skbs.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From d4ca73591916b760478d2b04334d5dcadc028e9c Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Wed, 19 Apr 2017 09:59:24 -0700
Subject: lan78xx: use skb_cow_head() to deal with cloned skbs

From: Eric Dumazet <edumazet@google.com>

commit d4ca73591916b760478d2b04334d5dcadc028e9c upstream.

We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.

skb_cow_head() is the proper helper to deal with this.

Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Cc: Woojung Huh <woojung.huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/net/usb/lan78xx.c |    9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

--- a/drivers/net/usb/lan78xx.c
+++ b/drivers/net/usb/lan78xx.c
@@ -2419,14 +2419,9 @@ static struct sk_buff *lan78xx_tx_prep(s
 {
 	u32 tx_cmd_a, tx_cmd_b;
 
-	if (skb_headroom(skb) < TX_OVERHEAD) {
-		struct sk_buff *skb2;
-
-		skb2 = skb_copy_expand(skb, TX_OVERHEAD, 0, flags);
+	if (skb_cow_head(skb, TX_OVERHEAD)) {
 		dev_kfree_skb_any(skb);
-		skb = skb2;
-		if (!skb)
-			return NULL;
+		return NULL;
 	}
 
 	if (lan78xx_linearize(skb) < 0)


Patches currently in stable-queue which might be from edumazet@google.com are

queue-4.9/lan78xx-use-skb_cow_head-to-deal-with-cloned-skbs.patch
queue-4.9/cx82310_eth-use-skb_cow_head-to-deal-with-cloned-skbs.patch
queue-4.9/sr9700-use-skb_cow_head-to-deal-with-cloned-skbs.patch
queue-4.9/smsc75xx-use-skb_cow_head-to-deal-with-cloned-skbs.patch