enic: Validate length of nl attributes in enic_set_vf_port

enic_set_vf_port assumes that the nl attribute IFLA_PORT_PROFILE
is of length PORT_PROFILE_MAX and that the nl attributes
IFLA_PORT_INSTANCE_UUID, IFLA_PORT_HOST_UUID are of length PORT_UUID_MAX.
These attributes are validated (in the function do_setlink in rtnetlink.c)
using the nla_policy ifla_port_policy. The policy defines IFLA_PORT_PROFILE
as NLA_STRING, IFLA_PORT_INSTANCE_UUID as NLA_BINARY and
IFLA_PORT_HOST_UUID as NLA_STRING. That means that the length validation
using the policy is for the max size of the attributes and not on exact
size so the length of these attributes might be less than the sizes that
enic_set_vf_port expects. This might cause an out of bands
read access in the memcpys of the data of these
attributes in enic_set_vf_port.

Fixes: f8bd9091 ("net: Add ndo_{set|get}_vf_port support for enic dynamic vnics")
Signed-off-by: Roded Zats <rzats@paloaltonetworks.com>
Link: https://lore.kernel.org/r/20240522073044.33519-1-rzats@paloaltonetworks.comSigned-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/cisco/enic/enic_main.c

@@ -1117,18 +1117,30 @@ static int enic_set_vf_port(struct net_device *netdev, int vf,
 	pp->request = nla_get_u8(port[IFLA_PORT_REQUEST]);
 
 	if (port[IFLA_PORT_PROFILE]) {
+		if (nla_len(port[IFLA_PORT_PROFILE]) != PORT_PROFILE_MAX) {
+			memcpy(pp, &prev_pp, sizeof(*pp));
+			return -EINVAL;
+		}
 		pp->set |= ENIC_SET_NAME;
 		memcpy(pp->name, nla_data(port[IFLA_PORT_PROFILE]),
 			PORT_PROFILE_MAX);
 	}
 
 	if (port[IFLA_PORT_INSTANCE_UUID]) {
+		if (nla_len(port[IFLA_PORT_INSTANCE_UUID]) != PORT_UUID_MAX) {
+			memcpy(pp, &prev_pp, sizeof(*pp));
+			return -EINVAL;
+		}
 		pp->set |= ENIC_SET_INSTANCE;
 		memcpy(pp->instance_uuid,
 			nla_data(port[IFLA_PORT_INSTANCE_UUID]), PORT_UUID_MAX);
 	}
 
 	if (port[IFLA_PORT_HOST_UUID]) {
+		if (nla_len(port[IFLA_PORT_HOST_UUID]) != PORT_UUID_MAX) {
+			memcpy(pp, &prev_pp, sizeof(*pp));
+			return -EINVAL;
+		}
 		pp->set |= ENIC_SET_HOST;
 		memcpy(pp->host_uuid,
 			nla_data(port[IFLA_PORT_HOST_UUID]), PORT_UUID_MAX);