From: Vlad Yasevich <vladislav.yasevich@hp.com>
Date: Mon, 25 Aug 2008 22:16:19 +0000 (-0700)
Subject: sctp: add verification checks to SCTP_AUTH_KEY option
X-Git-Tag: v2.6.27-rc5~30^2~11
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=30c2235cbc477d4629983d440cdc4f496fec9246;p=linux-2.6-omap-h63xx.git

sctp: add verification checks to SCTP_AUTH_KEY option

The structure used for SCTP_AUTH_KEY option contains a
length that needs to be verfied to prevent buffer overflow
conditions.  Spoted by Eugene Teo <eteo@redhat.com>.

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/sctp/auth.c b/net/sctp/auth.c
index 675a5c3e68a..1fcb4cf2f4c 100644
--- a/net/sctp/auth.c
+++ b/net/sctp/auth.c
@@ -80,6 +80,10 @@ static struct sctp_auth_bytes *sctp_auth_create_key(__u32 key_len, gfp_t gfp)
 {
 	struct sctp_auth_bytes *key;
 
+	/* Verify that we are not going to overflow INT_MAX */
+	if ((INT_MAX - key_len) < sizeof(struct sctp_auth_bytes))
+		return NULL;
+
 	/* Allocate the shared key */
 	key = kmalloc(sizeof(struct sctp_auth_bytes) + key_len, gfp);
 	if (!key)
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index bb5c9ef1304..afa952e726d 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -3144,6 +3144,11 @@ static int sctp_setsockopt_auth_key(struct sock *sk,
 		goto out;
 	}
 
+	if (authkey->sca_keylength > optlen) {
+		ret = -EINVAL;
+		goto out;
+	}
+
 	asoc = sctp_id2assoc(sk, authkey->sca_assoc_id);
 	if (!asoc && authkey->sca_assoc_id && sctp_style(sk, UDP)) {
 		ret = -EINVAL;