[NETLINK]: Make use of NLA_STRING/NLA_NUL_STRING attribute validation

Converts existing NLA_STRING attributes to use the new
validation features, saving a couple of temporary buffers.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 6 deletions

diff --git a/net/netlink/genetlink.c b/net/netlink/genetlink.c
index d32599116c56..3ac942cdb677 100644
--- a/net/netlink/genetlink.c
+++ b/net/netlink/genetlink.c
@@ -455,7 +455,8 @@ static struct sk_buff *ctrl_build_msg(struct genl_family *family, u32 pid,
 
 static struct nla_policy ctrl_policy[CTRL_ATTR_MAX+1] __read_mostly = {
         [CTRL_ATTR_FAMILY_ID]   = { .type = NLA_U16 },
-        [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_STRING },
+        [CTRL_ATTR_FAMILY_NAME] = { .type = NLA_NUL_STRING,
+                                    .len = GENL_NAMSIZ - 1 },
 };
 
 static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
@@ -470,12 +471,9 @@ static int ctrl_getfamily(struct sk_buff *skb, struct genl_info *info)
         }
 
         if (info->attrs[CTRL_ATTR_FAMILY_NAME]) {
-                char name[GENL_NAMSIZ];
-
-                if (nla_strlcpy(name, info->attrs[CTRL_ATTR_FAMILY_NAME],
-                                GENL_NAMSIZ) >= GENL_NAMSIZ)
-                        goto errout;
+                char *name;
 
+                name = nla_data(info->attrs[CTRL_ATTR_FAMILY_NAME]);
                 res = genl_family_find_byname(name);
         }