openwrt/target/linux/generic/patches-4.9/023-3-cx82310_eth-use-skb_cow_head-to-deal-with-cloned-skb.patch
Álvaro Fernández Rojas 2db05cd199 kernel: use skb_cow_head() to deal with cloned skbs
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 Ethernet<->WiFi bridge for Raspberry Pi and probably other devices.

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
2017-04-23 13:51:55 +02:00

36 lines
1.1 KiB
Diff

From a9e840a2081ed28c2b7caa6a9a0041c950b3c37d Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Wed, 19 Apr 2017 09:59:22 -0700
Subject: [PATCH] cx82310_eth: use skb_cow_head() to deal with cloned skbs
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: cc28a20e77b2 ("introduce cx82310_eth: Conexant CX82310-based ADSL router USB ethernet driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/usb/cx82310_eth.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)
--- a/drivers/net/usb/cx82310_eth.c
+++ b/drivers/net/usb/cx82310_eth.c
@@ -293,12 +293,9 @@ static struct sk_buff *cx82310_tx_fixup(
{
int len = skb->len;
- if (skb_headroom(skb) < 2) {
- struct sk_buff *skb2 = skb_copy_expand(skb, 2, 0, flags);
+ if (skb_cow_head(skb, 2)) {
dev_kfree_skb_any(skb);
- skb = skb2;
- if (!skb)
- return NULL;
+ return NULL;
}
skb_push(skb, 2);