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>
diff --git a/net/rose/rose_loopback.c b/net/rose/rose_loopback.c
index ae4a9d9..3444562 100644
--- a/net/rose/rose_loopback.c
+++ b/net/rose/rose_loopback.c
@@ -73,9 +73,20 @@
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);