[PATCH] dns_resolver: Do not accept domain names longer than 255 chars

[PATCH] dns_resolver: Do not accept domain names longer than 255 chars

[Manuel Schölling]

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>
---
 net/dns_resolver/dns_query.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/dns_resolver/dns_query.c b/net/dns_resolver/dns_query.c
index e7b6d53..e0fde29 100644
--- a/net/dns_resolver/dns_query.c
+++ b/net/dns_resolver/dns_query.c
@@ -94,7 +94,7 @@ int dns_query(const char *type, const char *name, size_t namelen,
 
 	if (!namelen)
 		namelen = strlen(name);
-	if (namelen < 3)
+	if (namelen < 3 || namelen > 255)
 		return -EINVAL;
 	desclen += namelen + 1;
 
-- 
1.7.10.4

[PATCH v2] dns_resolver: Do not accept domain names longer than 255 chars

[Manuel Schölling]

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>
---
 net/dns_resolver/dns_query.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

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 @@ int dns_query(const char *type, const char *name, size_t namelen,
 	}
 
 	if (!namelen)
-		namelen = strlen(name);
-	if (namelen < 3)
+		namelen = strnlen(name, 256);
+	if (namelen < 3 || namelen > 255)
 		return -EINVAL;
 	desclen += namelen + 1;
 
-- 
1.7.10.4

Re: [PATCH] dns_resolver: Do not accept domain names longer than 255 chars

[David Miller]

From: Manuel Schölling <manuel.schoelling@gmx.de>
Date: Sat, 31 May 2014 18:44:33 +0200

> 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>

Applied to net-next, thanks.