sctp: verify length provided in heartbeat information parameter
If the variable parameter length provided in the mandatory
heartbeat information parameter exceeds the calculated payload
length the packet has been corrupted. Reply with a parameter
length protocol violation message.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/sm_statefuns.c b/net/sctp/sm_statefuns.c
index b6adef8..e92079d 100644
--- a/net/sctp/sm_statefuns.c
+++ b/net/sctp/sm_statefuns.c
@@ -1055,6 +1055,7 @@
void *arg,
sctp_cmd_seq_t *commands)
{
+ sctp_paramhdr_t *param_hdr;
struct sctp_chunk *chunk = arg;
struct sctp_chunk *reply;
size_t paylen = 0;
@@ -1072,12 +1073,17 @@
* Information field copied from the received HEARTBEAT chunk.
*/
chunk->subh.hb_hdr = (sctp_heartbeathdr_t *) chunk->skb->data;
+ param_hdr = (sctp_paramhdr_t *) chunk->subh.hb_hdr;
paylen = ntohs(chunk->chunk_hdr->length) - sizeof(sctp_chunkhdr_t);
+
+ if (ntohs(param_hdr->length) > paylen)
+ return sctp_sf_violation_paramlen(net, ep, asoc, type, arg,
+ param_hdr, commands);
+
if (!pskb_pull(chunk->skb, paylen))
goto nomem;
- reply = sctp_make_heartbeat_ack(asoc, chunk,
- chunk->subh.hb_hdr, paylen);
+ reply = sctp_make_heartbeat_ack(asoc, chunk, param_hdr, paylen);
if (!reply)
goto nomem;