tipc: fix error handling of expanding buffer headroom

Coverity says:

*** CID 1338065:  Error handling issues  (CHECKED_RETURN)
/net/tipc/udp_media.c: 162 in tipc_udp_send_msg()
156     	struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value;
157     	struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
158     	struct sk_buff *clone;
159     	struct rtable *rt;
160
161     	if (skb_headroom(skb) < UDP_MIN_HEADROOM)
>>>     CID 1338065:  Error handling issues  (CHECKED_RETURN)
>>>     Calling "pskb_expand_head" without checking return value (as is done elsewhere 51 out of 56 times).
162     		pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
163
164     	clone = skb_clone(skb, GFP_ATOMIC);
165     	skb_set_inner_protocol(clone, htons(ETH_P_TIPC));
166     	ub = rcu_dereference_rtnl(b->media_ptr);
167     	if (!ub) {

When expanding buffer headroom over udp tunnel with pskb_expand_head(),
it's unfortunate that we don't check its return value. As a result, if
the function returns an error code due to the lack of memory, it may
cause unpredictable consequence as we unconditionally consider that
it's always successful.

Fixes: e53567948f ("tipc: conditionally expand buffer headroom over udp tunnel")
Reported-by: <scan-admin@coverity.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ying Xue 2015-11-24 13:57:57 +08:00 committed by David S. Miller
parent f4195d1eac
commit 7098356bac

View File

@ -158,8 +158,11 @@ static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
struct rtable *rt;
if (skb_headroom(skb) < UDP_MIN_HEADROOM)
pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
if (err)
goto tx_error;
}
skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
ub = rcu_dereference_rtnl(b->media_ptr);