rose: Add length checks to CALL_REQUEST parsing

Define some constant offsets for CALL_REQUEST based on the description
at <http://www.techfest.com/networking/wan/x25plp.htm> and the
definition of ROSE as using 10-digit (5-byte) addresses.  Use them
consistently.  Validate all implicit and explicit facilities lengths.
Validate the address length byte rather than either trusting or
assuming its value.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ben Hutchings
2011-03-20 06:48:05 +00:00
committed by David S. Miller
parent be20250c13
commit e0bccd315d
5 changed files with 90 additions and 44 deletions

View File

@@ -73,9 +73,20 @@ static void rose_loopback_timer(unsigned long param)
unsigned int lci_i, lci_o;
while ((skb = skb_dequeue(&loopback_queue)) != NULL) {
if (skb->len < ROSE_MIN_LEN) {
kfree_skb(skb);
continue;
}
lci_i = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF);
frametype = skb->data[2];
dest = (rose_address *)(skb->data + 4);
if (frametype == ROSE_CALL_REQUEST &&
(skb->len <= ROSE_CALL_REQ_FACILITIES_OFF ||
skb->data[ROSE_CALL_REQ_ADDR_LEN_OFF] !=
ROSE_CALL_REQ_ADDR_LEN_VAL)) {
kfree_skb(skb);
continue;
}
dest = (rose_address *)(skb->data + ROSE_CALL_REQ_DEST_ADDR_OFF);
lci_o = ROSE_DEFAULT_MAXVC + 1 - lci_i;
skb_reset_transport_header(skb);