[PATCH 4.4 281/312] net: bridge: dont increment tx_dropped in br_do_proxy_arp

From: Greg Kroah-Hartman
Date: Fri May 08 2020 - 08:47:44 EST


From: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>

commit 85a3d4a9356b595d5440c3f1bf07ee7cecca1567 upstream.

pskb_may_pull may fail due to various reasons (e.g. alloc failure), but the
skb isn't changed/dropped and processing continues so we shouldn't
increment tx_dropped.

CC: Kyeyoon Park <kyeyoonp@xxxxxxxxxxxxxx>
CC: Roopa Prabhu <roopa@xxxxxxxxxxxxxxxxxxx>
CC: Stephen Hemminger <stephen@xxxxxxxxxxxxxxxxxx>
CC: bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 958501163ddd ("bridge: Add support for IEEE 802.11 Proxy ARP")
Signed-off-by: Nikolay Aleksandrov <nikolay@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/bridge/br_input.c | 7 ++-----
1 file changed, 2 insertions(+), 5 deletions(-)

--- a/net/bridge/br_input.c
+++ b/net/bridge/br_input.c
@@ -78,13 +78,10 @@ static void br_do_proxy_arp(struct sk_bu

BR_INPUT_SKB_CB(skb)->proxyarp_replied = false;

- if (dev->flags & IFF_NOARP)
+ if ((dev->flags & IFF_NOARP) ||
+ !pskb_may_pull(skb, arp_hdr_len(dev)))
return;

- if (!pskb_may_pull(skb, arp_hdr_len(dev))) {
- dev->stats.tx_dropped++;
- return;
- }
parp = arp_hdr(skb);

if (parp->ar_pro != htons(ETH_P_IP) ||