p9_client_readdir() fix

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

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/net/9p/client.c b/net/9p/client.c
index 3ce672af1596cfdb8fbd67ce558366e7997b7695..8e5c6a8d0a3733d03a9c36ca8854f828cb8cc678 100644 (file)
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -2101,6 +2101,10 @@ int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset)
                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);