tipc: fix dereference before check warning

This fixes the following Smatch warning:
net/tipc/link.c:2364 tipc_link_recv_fragment()
    warn: variable dereferenced before check '*head' (see line 2361)

A null pointer might be passed to skb_try_coalesce if
a malicious sender injects orphan fragments on a link.

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Erik Hugne 2013-11-13 09:35:11 +01:00 committed by David S. Miller
parent c9e9042994
commit 3db0a197ed

View file

@ -2358,7 +2358,8 @@ int tipc_link_recv_fragment(struct sk_buff **head, struct sk_buff **tail,
*head = frag;
skb_frag_list_init(*head);
return 0;
} else if (skb_try_coalesce(*head, frag, &headstolen, &delta)) {
} else if (*head &&
skb_try_coalesce(*head, frag, &headstolen, &delta)) {
kfree_skb_partial(frag, headstolen);
} else {
if (!*head)