kernel: use skb_cow_head() to deal with cloned skbs

[openwrt/openwrt.git] / target / linux / generic / patches-4.4 / 030-3-cx82310_eth-use-skb_cow_head-to-deal-with-cloned-skb.patch

diff --git a/target/linux/generic/patches-4.4/030-3-cx82310_eth-use-skb_cow_head-to-deal-with-cloned-skb.patch b/target/linux/generic/patches-4.4/030-3-cx82310_eth-use-skb_cow_head-to-deal-with-cloned-skb.patch
new file mode 100644 (file)
index 0000000..aee8aa9
--- /dev/null
+++ b/target/linux/generic/patches-4.4/030-3-cx82310_eth-use-skb_cow_head-to-deal-with-cloned-skb.patch
@@ -0,0 +1,35 @@
+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);
+