[PATCH] xprtrdma: Make rpcrdma_sendctxs_destroy() more robust

[Dan Carpenter <dan.carpenter@oracle.com>]

There was a double free in the error handling here recently.  It was
a bit subtle which function was supposed to call rpcrdma_sendctxs_destroy()
so it was called in both.

This patch makes it so we can call rpcrdma_sendctxs_destroy() twice
in a row without crashing.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 net/sunrpc/xprtrdma/verbs.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c
index 7749a2bf6887..d05f4885548d 100644
--- a/net/sunrpc/xprtrdma/verbs.c
+++ b/net/sunrpc/xprtrdma/verbs.c
@@ -802,9 +802,12 @@ static void rpcrdma_sendctxs_destroy(struct rpcrdma_buffer *buf)
 {
 	unsigned long i;
 
+	if (!buf->rb_sc_ctxs)
+		return;
 	for (i = 0; i <= buf->rb_sc_last; i++)
 		kfree(buf->rb_sc_ctxs[i]);
 	kfree(buf->rb_sc_ctxs);
+	buf->rb_sc_ctxs = NULL;
 }
 
 static struct rpcrdma_sendctx *rpcrdma_sendctx_create(struct rpcrdma_ia *ia)
-- 
2.17.1