X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=net%2Fipv4%2Fnetfilter%2Fnf_nat_snmp_basic.c;h=ffeaffc3fffe6c31c78e858b9a1fa61fe71ba03e;hb=252815b0cfe711001eff0327872209986b36d490;hp=5daefad3d1936393139baf80d48cff263c5262cd;hpb=36a23fc8aa0c72ecafe7aaee0a823b03b301e1df;p=linux-2.6

diff --git a/net/ipv4/netfilter/nf_nat_snmp_basic.c b/net/ipv4/netfilter/nf_nat_snmp_basic.c
index 5daefad3d1..ffeaffc3ff 100644
--- a/net/ipv4/netfilter/nf_nat_snmp_basic.c
+++ b/net/ipv4/netfilter/nf_nat_snmp_basic.c
@@ -232,6 +232,11 @@ static unsigned char asn1_length_decode(struct asn1_ctx *ctx,
 			}
 		}
 	}
+
+	/* don't trust len bigger than ctx buffer */
+	if (*len > ctx->end - ctx->pointer)
+		return 0;
+
 	return 1;
 }
 
@@ -250,6 +255,10 @@ static unsigned char asn1_header_decode(struct asn1_ctx *ctx,
 	if (!asn1_length_decode(ctx, &def, &len))
 		return 0;
 
+	/* primitive shall be definite, indefinite shall be constructed */
+	if (*con == ASN1_PRI && !def)
+		return 0;
+
 	if (def)
 		*eoc = ctx->pointer + len;
 	else
@@ -430,10 +439,15 @@ static unsigned char asn1_oid_decode(struct asn1_ctx *ctx,
 				     unsigned int *len)
 {
 	unsigned long subid;
-	unsigned int  size;
 	unsigned long *optr;
+	size_t size;
 
 	size = eoc - ctx->pointer + 1;
+
+	/* first subid actually encodes first two subids */
+	if (size < 2 || size > ULONG_MAX/sizeof(unsigned long))
+		return 0;
+
 	*oid = kmalloc(size * sizeof(unsigned long), GFP_ATOMIC);
 	if (*oid == NULL) {
 		if (net_ratelimit())