net/9p: Return error on read with NULL buffer

This patch ensures that a read(fd, NULL, 10) returns  EFAULT on a 9p file.

Signed-off-by: Sanchit Garg <sancgarg@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

diff --git a/net/9p/client.c b/net/9p/client.c
index 8df80fb..a848bca 100644 (file)
--- a/net/9p/client.c
+++ b/net/9p/client.c
@@ -1286,16 +1286,13 @@ p9_client_read(struct p9_fid *fid, char *data, char __user *udata, u64 offset,
 
        if (data) {
                memmove(data, dataptr, count);
-       }
-
-       if (udata) {
+       } else {
                err = copy_to_user(udata, dataptr, count);
                if (err) {
                        err = -EFAULT;
                        goto free_and_error;
                }
        }
-
        p9_free_req(clnt, req);
        return count;