1 files changed, 15 insertions, 0 deletions
diff --git a/net/rds/recv.c b/net/rds/recv.c
index 4b3f9e4a8bfd..cf3884d87931 100644
--- a/net/rds/recv.c
+++ b/net/rds/recv.c
@@ -399,6 +399,21 @@ void rds_recv_incoming(struct rds_connection *conn, struct in6_addr *saddr,
 		goto out;
 	}
 
+	/*
+	 * rds_find_bound() uses a global (netns-agnostic) hash table.
+	 * An RDS connection created in netns A can match a socket bound
+	 * in the init netns, delivering inc cross-netns with inc->i_conn
+	 * pointing into netns A.  When cleanup_net() then frees that conn,
+	 * any subsequent dereference of inc->i_conn is a use-after-free.
+	 * Drop the inc if the receiving socket lives in a different netns.
+	 */
+	if (!net_eq(sock_net(rds_rs_to_sk(rs)), rds_conn_net(conn))) {
+		rds_stats_inc(s_recv_drop_no_sock);
+		rds_sock_put(rs);
+		rs = NULL;
+		goto out;
+	}
+
 	/* Process extension headers */
 	rds_recv_incoming_exthdrs(inc, rs);