rtnetlink: Mask the rta_type when range checking

[ Upstream commit a5b8db91442fce9c9713fcd656c3698f1adde1d6 ]

Range/validity checks on rta_type in rtnetlink_rcv_msg() do
not account for flags that may be set.  This causes the function
to return -EINVAL when flags are set on the type (for example
NLA_F_NESTED).

Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 92f8ed8..3b5e680 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -2042,7 +2042,7 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                struct rtattr *attr = (void *)nlh + NLMSG_ALIGN(min_len);
 
                while (RTA_OK(attr, attrlen)) {
-                       unsigned flavor = attr->rta_type;
+                       unsigned int flavor = attr->rta_type & NLA_TYPE_MASK;
                        if (flavor) {
                                if (flavor > rta_max[sz_idx])
                                        return -EINVAL;