net/rds: fix unaligned memory access

[cascardo/linux.git] / net / rds / ib_cm.c

diff --git a/net/rds/ib_cm.c b/net/rds/ib_cm.c
index 31b74f5..29144a6 100644 (file)
--- a/net/rds/ib_cm.c
+++ b/net/rds/ib_cm.c
@@ -183,8 +183,17 @@ void rds_ib_cm_connect_complete(struct rds_connection *conn, struct rdma_cm_even
 
        /* If the peer gave us the last packet it saw, process this as if
         * we had received a regular ACK. */
-       if (dp && dp->dp_ack_seq)
-               rds_send_drop_acked(conn, be64_to_cpu(dp->dp_ack_seq), NULL);
+       if (dp) {
+               /* dp structure start is not guaranteed to be 8 bytes aligned.
+                * Since dp_ack_seq is 64-bit extended load operations can be
+                * used so go through get_unaligned to avoid unaligned errors.
+                */
+               u64 dp_ack_seq = get_unaligned(&dp->dp_ack_seq);
+
+               if (dp_ack_seq)
+                       rds_send_drop_acked(conn, be64_to_cpu(dp_ack_seq),
+                                           NULL);
+       }
 
        rds_connect_complete(conn);
 }