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authorHerbert Xu <herbert@gondor.apana.org.au>2008-01-05 23:14:44 -0800
committerDavid S. Miller <davem@davemloft.net>2008-01-08 23:29:57 -0800
commitf844c74fe07321953e2dd227fe35280075f18f60 (patch)
tree045fedb426c7990ad254520cb413010acbbe0ab8 /net
parentcb77df3ec88f07c6141924dfe6fd96a2f541cc09 (diff)
downloadlinux-f844c74fe07321953e2dd227fe35280075f18f60.tar.gz
[IPV4] raw: Strengthen check on validity of iph->ihl
We currently check that iph->ihl is bounded by the real length and that
the real length is greater than the minimum IP header length.  However,
we did not check the caes where iph->ihl is less than the minimum IP
header length.

This breaks because some ip_fast_csum implementations assume that which
is quite reasonable.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/ipv4/raw.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 66b42f547bf9..e7050f8eabeb 100644
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -271,6 +271,7 @@ static int raw_send_hdrinc(struct sock *sk, void *from, size_t length,
 	int hh_len;
 	struct iphdr *iph;
 	struct sk_buff *skb;
+	unsigned int iphlen;
 	int err;
 
 	if (length > rt->u.dst.dev->mtu) {
@@ -304,7 +305,8 @@ static int raw_send_hdrinc(struct sock *sk, void *from, size_t length,
 		goto error_fault;
 
 	/* We don't modify invalid header */
-	if (length >= sizeof(*iph) && iph->ihl * 4U <= length) {
+	iphlen = iph->ihl * 4;
+	if (iphlen >= sizeof(*iph) && iphlen <= length) {
 		if (!iph->saddr)
 			iph->saddr = rt->rt_src;
 		iph->check   = 0;