RDS/IB: Improve RDS protocol version checking
RDS on IB uses privdata to do protocol version negotiation. Apparently
the IB stack will return a larger privdata buffer than the struct we were
expecting. Just to be extra-sure, this patch adds some checks in this area.
Signed-off-by: Andy Grover <andy.grover@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/rds/ib_cm.c b/net/rds/ib_cm.c
index 605c032..0964ac5 100644
--- a/net/rds/ib_cm.c
+++ b/net/rds/ib_cm.c
@@ -98,7 +98,7 @@
struct ib_qp_attr qp_attr;
int err;
- if (event->param.conn.private_data_len) {
+ if (event->param.conn.private_data_len >= sizeof(*dp)) {
dp = event->param.conn.private_data;
rds_ib_set_protocol(conn,
@@ -344,19 +344,32 @@
return ret;
}
-static u32 rds_ib_protocol_compatible(const struct rds_ib_connect_private *dp)
+static u32 rds_ib_protocol_compatible(struct rdma_cm_event *event)
{
+ const struct rds_ib_connect_private *dp = event->param.conn.private_data;
u16 common;
u32 version = 0;
- /* rdma_cm private data is odd - when there is any private data in the
+ /*
+ * rdma_cm private data is odd - when there is any private data in the
* request, we will be given a pretty large buffer without telling us the
* original size. The only way to tell the difference is by looking at
* the contents, which are initialized to zero.
* If the protocol version fields aren't set, this is a connection attempt
* from an older version. This could could be 3.0 or 2.0 - we can't tell.
- * We really should have changed this for OFED 1.3 :-( */
- if (dp->dp_protocol_major == 0)
+ * We really should have changed this for OFED 1.3 :-(
+ */
+
+ /* Be paranoid. RDS always has privdata */
+ if (!event->param.conn.private_data_len) {
+ printk(KERN_NOTICE "RDS incoming connection has no private data, "
+ "rejecting\n");
+ return 0;
+ }
+
+ /* Even if len is crap *now* I still want to check it. -ASG */
+ if (event->param.conn.private_data_len < sizeof (*dp)
+ || dp->dp_protocol_major == 0)
return RDS_PROTOCOL_3_0;
common = be16_to_cpu(dp->dp_protocol_minor_mask) & RDS_IB_SUPPORTED_PROTOCOLS;
@@ -388,7 +401,7 @@
int err, destroy = 1;
/* Check whether the remote protocol version matches ours. */
- version = rds_ib_protocol_compatible(dp);
+ version = rds_ib_protocol_compatible(event);
if (!version)
goto out;