From f5eb917b861828da18dc28854308068c66d1449a Mon Sep 17 00:00:00 2001 From: John Hughes Date: Wed, 7 Apr 2010 21:29:25 -0700 Subject: 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 Signed-off-by: David S. Miller --- net/x25/x25_in.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'net/x25/x25_in.c') diff --git a/net/x25/x25_in.c b/net/x25/x25_in.c index 96d922783547..b39072f3a297 100644 --- a/net/x25/x25_in.c +++ b/net/x25/x25_in.c @@ -89,6 +89,7 @@ static int x25_queue_rx_frame(struct sock *sk, struct sk_buff *skb, int more) 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 @@ static int x25_state1_machine(struct sock *sk, struct sk_buff *skb, int frametyp * 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. */ -- cgit v1.2.1