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| author | Ben Hutchings <ben@decadent.org.uk> | 2011-03-20 06:48:05 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-03-28 00:59:04 (GMT) |
| commit | e0bccd315db0c2f919e7fcf9cb60db21d9986f52 (patch) | |
| tree | 8cf512f43221087f964c0f55c7665e293e96921b /net/rose/rose_route.c | |
| parent | be20250c13f88375345ad99950190685eda51eb8 (diff) | |
| download | linux-e0bccd315db0c2f919e7fcf9cb60db21d9986f52.tar.xz | |
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>
Diffstat (limited to 'net/rose/rose_route.c')
| -rw-r--r-- | net/rose/rose_route.c | 20 |
1 files changed, 13 insertions, 7 deletions
diff --git a/net/rose/rose_route.c b/net/rose/rose_route.c index 88a77e9..08dcd2f 100644 --- a/net/rose/rose_route.c +++ b/net/rose/rose_route.c @@ -861,7 +861,7 @@ int rose_route_frame(struct sk_buff *skb, ax25_cb *ax25) unsigned int lci, new_lci; unsigned char cause, diagnostic; struct net_device *dev; - int len, res = 0; + int res = 0; char buf[11]; #if 0 @@ -869,10 +869,17 @@ int rose_route_frame(struct sk_buff *skb, ax25_cb *ax25) return res; #endif + if (skb->len < ROSE_MIN_LEN) + return res; frametype = skb->data[2]; lci = ((skb->data[0] << 8) & 0xF00) + ((skb->data[1] << 0) & 0x0FF); - src_addr = (rose_address *)(skb->data + 9); - dest_addr = (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)) + return res; + src_addr = (rose_address *)(skb->data + ROSE_CALL_REQ_SRC_ADDR_OFF); + dest_addr = (rose_address *)(skb->data + ROSE_CALL_REQ_DEST_ADDR_OFF); spin_lock_bh(&rose_neigh_list_lock); spin_lock_bh(&rose_route_list_lock); @@ -1010,12 +1017,11 @@ int rose_route_frame(struct sk_buff *skb, ax25_cb *ax25) goto out; } - len = (((skb->data[3] >> 4) & 0x0F) + 1) >> 1; - len += (((skb->data[3] >> 0) & 0x0F) + 1) >> 1; - memset(&facilities, 0x00, sizeof(struct rose_facilities_struct)); - if (!rose_parse_facilities(skb->data + len + 4, &facilities)) { + if (!rose_parse_facilities(skb->data + ROSE_CALL_REQ_FACILITIES_OFF, + skb->len - ROSE_CALL_REQ_FACILITIES_OFF, + &facilities)) { rose_transmit_clear_request(rose_neigh, lci, ROSE_INVALID_FACILITY, 76); goto out; } |