From 7098356baca723513e97ca0020df4e18bc353be3 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Tue, 24 Nov 2015 13:57:57 +0800 Subject: [PATCH] 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: e53567948f82 ("tipc: conditionally expand buffer headroom over udp tunnel") Reported-by: Cc: Stephen Hemminger Signed-off-by: Ying Xue Signed-off-by: David S. Miller --- net/tipc/udp_media.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c index ad2719ad4c1b..70c03271b798 100644 --- a/net/tipc/udp_media.c +++ b/net/tipc/udp_media.c @@ -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); -- 2.11.0