1 files changed, 63 insertions, 5 deletions

diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index 9796f3e..cbddd0c 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -47,6 +47,7 @@
 #include <linux/netdevice.h>
 #include <linux/if_arp.h>
 #include <linux/skbuff.h>
+#include <linux/slab.h>
 #include <net/sock.h>
 #include <net/tcp_states.h>
 #include <asm/uaccess.h>
@@ -82,6 +83,41 @@ struct compat_x25_subscrip_struct {
 };
 #endif
 
+
+int x25_parse_address_block(struct sk_buff *skb,
+		struct x25_address *called_addr,
+		struct x25_address *calling_addr)
+{
+	unsigned char len;
+	int needed;
+	int rc;
+
+	if (skb->len < 1) {
+		/* packet has no address block */
+		rc = 0;
+		goto empty;
+	}
+
+	len = *skb->data;
+	needed = 1 + (len >> 4) + (len & 0x0f);
+
+	if (skb->len < needed) {
+		/* packet is too short to hold the addresses it claims
+		   to hold */
+		rc = -1;
+		goto empty;
+	}
+
+	return x25_addr_ntoa(skb->data, called_addr, calling_addr);
+
+empty:
+	*called_addr->x25_addr = 0;
+	*calling_addr->x25_addr = 0;
+
+	return rc;
+}
+
+
 int x25_addr_ntoa(unsigned char *p, struct x25_address *called_addr,
 		  struct x25_address *calling_addr)
 {
@@ -553,7 +589,8 @@ static int x25_create(struct net *net, struct socket *sock, int protocol,
 	x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE;
 	x25->facilities.pacsize_in  = X25_DEFAULT_PACKET_SIZE;
 	x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE;
-	x25->facilities.throughput  = X25_DEFAULT_THROUGHPUT;
+	x25->facilities.throughput  = 0;	/* by default don't negotiate
+						   throughput */
 	x25->facilities.reverse     = X25_DEFAULT_REVERSE;
 	x25->dte_facilities.calling_len = 0;
 	x25->dte_facilities.called_len = 0;
@@ -921,16 +958,26 @@ int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
 	/*
 	 *	Extract the X.25 addresses and convert them to ASCII strings,
 	 *	and remove them.
+	 *
+	 *	Address block is mandatory in call request packets
 	 */
-	addr_len = x25_addr_ntoa(skb->data, &source_addr, &dest_addr);
+	addr_len = x25_parse_address_block(skb, &source_addr, &dest_addr);
+	if (addr_len <= 0)
+		goto out_clear_request;
 	skb_pull(skb, addr_len);
 
 	/*
 	 *	Get the length of the facilities, skip past them for the moment
 	 *	get the call user data because this is needed to determine
 	 *	the correct listener
+	 *
+	 *	Facilities length is mandatory in call request packets
 	 */
+	if (skb->len < 1)
+		goto out_clear_request;
 	len = skb->data[0] + 1;
+	if (skb->len < len)
+		goto out_clear_request;
 	skb_pull(skb,len);
 
 	/*
@@ -1414,9 +1461,20 @@ static int x25_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
 			if (facilities.winsize_in < 1 ||
 			    facilities.winsize_in > 127)
 				break;
-			if (facilities.throughput < 0x03 ||
-			    facilities.throughput > 0xDD)
-				break;
+			if (facilities.throughput) {
+				int out = facilities.throughput & 0xf0;
+				int in  = facilities.throughput & 0x0f;
+				if (!out)
+					facilities.throughput |=
+						X25_DEFAULT_THROUGHPUT << 4;
+				else if (out < 0x30 || out > 0xD0)
+					break;
+				if (!in)
+					facilities.throughput |=
+						X25_DEFAULT_THROUGHPUT;
+				else if (in < 0x03 || in > 0x0D)
+					break;
+			}
 			if (facilities.reverse &&
 				(facilities.reverse & 0x81) != 0x81)
 				break;