Commit f844c74f authored Jan 05, 2008 by Herbert Xu Committed by David S. Miller Jan 08, 2008

[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>

parent cb77df3e

net/ipv4/raw.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -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;