From: Chuck Lever <chuck.lever@oracle.com>
Date: Mon, 16 Oct 2017 15:01:06 -0400
Subject: [PATCH] xprtrdma: Throw away reply when version is unrecognized
Git-commit: 61433af56077f5fd8815281b44938d84feb04687
Patch-mainline: v4.15-rc1
References: git-fixes

A reply with an unrecognized value in the version field means the
transport header is potentially garbled and therefore all the fields
are untrustworthy.

Fixes: 59aa1f9a3cce3 ("xprtrdma: Properly handle RDMA_ERROR ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Acked-by: NeilBrown <neilb@suse.com>

---
 net/sunrpc/xprtrdma/rpc_rdma.c |   17 ++++++++---------
 1 file changed, 8 insertions(+), 9 deletions(-)

--- a/net/sunrpc/xprtrdma/rpc_rdma.c
+++ b/net/sunrpc/xprtrdma/rpc_rdma.c
@@ -1248,6 +1248,9 @@ rpcrdma_reply_handler(struct work_struct
 	p++;	/* credits */
 	proc = *p++;
 
+	if (vers != rpcrdma_version)
+		goto out_badversion;
+
 	if (rpcrdma_is_bcall(r_xprt, rep, xid, proc))
 		return;
 
@@ -1280,8 +1283,6 @@ rpcrdma_reply_handler(struct work_struct
 	}
 
 	xprt->reestablish_timeout = 0;
-	if (vers != rpcrdma_version)
-		goto out_badversion;
 
 	switch (proc) {
 	case rdma_msg:
@@ -1321,17 +1322,15 @@ out_badstatus:
 	}
 	return;
 
-/* If the incoming reply terminated a pending RPC, the next
- * RPC call will post a replacement receive buffer as it is
- * being marshaled.
- */
 out_badversion:
 	dprintk("RPC:       %s: invalid version %d\n",
 		__func__, be32_to_cpu(vers));
-	status = -EIO;
-	r_xprt->rx_stats.bad_reply_count++;
-	goto out;
+	goto repost;
 
+/* If the incoming reply terminated a pending RPC, the next
+ * RPC call will post a replacement receive buffer as it is
+ * being marshaled.
+ */
 out_badheader:
 	dprintk("RPC: %5u %s: invalid rpcrdma reply (type %u)\n",
 		rqst->rq_task->tk_pid, __func__, be32_to_cpu(proc));