[PATCH 4.10 52/62] p9_client_readdir() fix

[Greg Kroah-Hartman]

4.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

commit 71d6ad08379304128e4bdfaf0b4185d54375423e upstream.

Don't assume that server is sane and won't return more data than
asked for.

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/9p/client.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -2101,6 +2101,10 @@ int p9_client_readdir(struct p9_fid *fid
 		trace_9p_protocol_dump(clnt, req->rc);
 		goto free_and_error;
 	}
+	if (rsize < count) {
+		pr_err("bogus RREADDIR count (%d > %d)\n", count, rsize);
+		count = rsize;
+	}
 
 	p9_debug(P9_DEBUG_9P, "<<< RREADDIR count %d\n", count);