nfsd4: require version 4 when enabling or disabling minorversion

The current code will allow silly things like:

	echo "+2 +3 +4 +7.1">/proc/fs/nfsd/versions

Reported-by: Fan Chaoting <fanchaoting@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 74934284d9a7b27433a172231d88647b4a414aec..65889ec1d28e1852c84835239205acd0b96f4c94 100644 (file)
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -534,7 +534,7 @@ static ssize_t __write_versions(struct file *file, char *buf, size_t size)
                        else
                                num = simple_strtol(vers, &minorp, 0);
                        if (*minorp == '.') {
-                               if (num < 4)
+                               if (num != 4)
                                        return -EINVAL;
                                minor = simple_strtoul(minorp+1, NULL, 0);
                                if (minor == 0)