RDMA/CMA: Canonize IPv4 on IPV6 sockets properly

When accepting a new IPv4 connect to an IPv6 socket, the CMA tries to
canonize the address family to IPv4, but does not properly process
the listening sockaddr to get the listening port, and does not properly
set the address family of the canonized sockaddr.

Fixes: e51060f0 ("IB: IP address based RDMA connection manager")

Cc: <stable@vger.kernel.org>
Reported-By: Yotam Kenneth <yotamke@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tested-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/core/cma.c

@@ -859,19 +859,27 @@ static void cma_save_ib_info(struct rdma_cm_id *id, struct rdma_cm_id *listen_id
 	memcpy(&ib->sib_addr, &path->dgid, 16);
 }
 
+static __be16 ss_get_port(const struct sockaddr_storage *ss)
+{
+	if (ss->ss_family == AF_INET)
+		return ((struct sockaddr_in *)ss)->sin_port;
+	else if (ss->ss_family == AF_INET6)
+		return ((struct sockaddr_in6 *)ss)->sin6_port;
+	BUG();
+}
+
 static void cma_save_ip4_info(struct rdma_cm_id *id, struct rdma_cm_id *listen_id,
 			      struct cma_hdr *hdr)
 {
-	struct sockaddr_in *listen4, *ip4;
+	struct sockaddr_in *ip4;
 
-	listen4 = (struct sockaddr_in *) &listen_id->route.addr.src_addr;
 	ip4 = (struct sockaddr_in *) &id->route.addr.src_addr;
-	ip4->sin_family = listen4->sin_family;
+	ip4->sin_family = AF_INET;
 	ip4->sin_addr.s_addr = hdr->dst_addr.ip4.addr;
-	ip4->sin_port = listen4->sin_port;
+	ip4->sin_port = ss_get_port(&listen_id->route.addr.src_addr);
 
 	ip4 = (struct sockaddr_in *) &id->route.addr.dst_addr;
-	ip4->sin_family = listen4->sin_family;
+	ip4->sin_family = AF_INET;
 	ip4->sin_addr.s_addr = hdr->src_addr.ip4.addr;
 	ip4->sin_port = hdr->port;
 }
@@ -879,16 +887,15 @@ static void cma_save_ip4_info(struct rdma_cm_id *id, struct rdma_cm_id *listen_i
 static void cma_save_ip6_info(struct rdma_cm_id *id, struct rdma_cm_id *listen_id,
 			      struct cma_hdr *hdr)
 {
-	struct sockaddr_in6 *listen6, *ip6;
+	struct sockaddr_in6 *ip6;
 
-	listen6 = (struct sockaddr_in6 *) &listen_id->route.addr.src_addr;
 	ip6 = (struct sockaddr_in6 *) &id->route.addr.src_addr;
-	ip6->sin6_family = listen6->sin6_family;
+	ip6->sin6_family = AF_INET6;
 	ip6->sin6_addr = hdr->dst_addr.ip6;
-	ip6->sin6_port = listen6->sin6_port;
+	ip6->sin6_port = ss_get_port(&listen_id->route.addr.src_addr);
 
 	ip6 = (struct sockaddr_in6 *) &id->route.addr.dst_addr;
-	ip6->sin6_family = listen6->sin6_family;
+	ip6->sin6_family = AF_INET6;
 	ip6->sin6_addr = hdr->src_addr.ip6;
 	ip6->sin6_port = hdr->port;
 }