Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > > ip_fast_csum() called from raw_send_hdrinc() from raw_sendmsg() ran through > the page boundary into unmapped page... Bloody odd, that, seeing that > we have checked iph->ihl * 4U <= length and had done > err = memcpy_fromiovecend((void *)iph, from, 0, length); > before the > iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl); > that had triggered that crap.. Actually if you read the code for ip_fast_csum it's obvious what has happened. %o1 == iph->ihl contains the value 2 which is bogus. [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@xxxxxxxxxxxxxxxxxxx> Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c index 66b42f5..e7050f8 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; - To unsubscribe from this list: send the line "unsubscribe sparclinux" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
