x25: Patch to fix bug 15678 - x25 accesses fields beyond end of packet.
Here is a patch to stop X.25 examining fields beyond the end of the packet.
For example, when a simple CALL ACCEPTED was received:
10 10 0f
x25_parse_facilities was attempting to decode the FACILITIES field, but this
packet contains no facilities field.
Signed-off-by: John Hughes <john@calva.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/x25/x25_in.c b/net/x25/x25_in.c
index 96d9227..b39072f 100644
--- a/net/x25/x25_in.c
+++ b/net/x25/x25_in.c
@@ -89,6 +89,7 @@
static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametype)
{
struct x25_address source_addr, dest_addr;
+ int len;
switch (frametype) {
case X25_CALL_ACCEPTED: {
@@ -106,11 +107,17 @@
* Parse the data in the frame.
*/
skb_pull(skb, X25_STD_MIN_LEN);
- skb_pull(skb, x25_addr_ntoa(skb->data, &source_addr, &dest_addr));
- skb_pull(skb,
- x25_parse_facilities(skb, &x25->facilities,
+
+ len = x25_parse_address_block(skb, &source_addr,
+ &dest_addr);
+ if (len > 0)
+ skb_pull(skb, len);
+
+ len = x25_parse_facilities(skb, &x25->facilities,
&x25->dte_facilities,
- &x25->vc_facil_mask));
+ &x25->vc_facil_mask);
+ if (len > 0)
+ skb_pull(skb, len);
/*
* Copy any Call User Data.
*/