openwrt/target/linux/generic/patches-4.9/023-4-sr9700-use-skb_cow_head-to-deal-with-cloned-skbs.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

38 lines
1.2 KiB
Diff

From d532c1082f68176363ed766d09bf187616e282fe Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Wed, 19 Apr 2017 09:59:23 -0700
Subject: [PATCH] sr9700: 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: c9b37458e956 ("USB2NET : SR9700 : One chip USB 1.1 USB2NET SR9700Device Driver Support")
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/sr9700.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)
--- a/drivers/net/usb/sr9700.c
+++ b/drivers/net/usb/sr9700.c
@@ -456,14 +456,9 @@ static struct sk_buff *sr9700_tx_fixup(s
len = skb->len;
- if (skb_headroom(skb) < SR_TX_OVERHEAD) {
- struct sk_buff *skb2;
-
- skb2 = skb_copy_expand(skb, SR_TX_OVERHEAD, 0, flags);
+ if (skb_cow_head(skb, SR_TX_OVERHEAD)) {
dev_kfree_skb_any(skb);
- skb = skb2;
- if (!skb)
- return NULL;
+ return NULL;
}
__skb_push(skb, SR_TX_OVERHEAD);