1 files changed, 62 insertions, 5 deletions

diff --git a/net/x25/af_x25.c b/net/x25/af_x25.c
index e56f711baccc..cbddd0cb83f1 100644
--- a/net/x25/af_x25.c
+++ b/net/x25/af_x25.c
@@ -83,6 +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)
 {
@@ -554,7 +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;
@@ -922,16 +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);
 
         /*
@@ -1415,9 +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;