commit 9638f6713ff556bdc34e9d18eeb7c1b25b35e5ce
author Manuel Schölling <manuel.schoelling@gmx.de> Sat May 31 23:37:40 2014 +0200
committer David S. Miller <davem@davemloft.net> Thu Jun 05 00:05:53 2014 -0700
tree 15d915b3f585a6ad528bfa936a7d44bec9093ab2
parent 555878b9ee83b08701100baa0fd79d3954a37ce7

dns_resolver: Do not accept domain names longer than 255 chars

According to RFC1035 "[...] the total length of a domain name (i.e.,
label octets and label length octets) is restricted to 255 octets or
less."

Signed-off-by: Manuel Schölling <manuel.schoelling@gmx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/dns_resolver/dns_query.c

diff --git a/net/dns_resolver/dns_query.c b/net/dns_resolver/dns_query.c
index e7b6d53..5b49958 100644
--- a/net/dns_resolver/dns_query.c
+++ b/net/dns_resolver/dns_query.c
@@ -93,8 +93,8 @@
 	}
 
 	if (!namelen)
-		namelen = strlen(name);
-	if (namelen < 3)
+		namelen = strnlen(name, 256);
+	if (namelen < 3 || namelen > 255)
 		return -EINVAL;
 	desclen += namelen + 1;