[IPv4] fib: Fix out of bound access of fib_props[]

Fixes a typo which caused fib_props[] to have the wrong size
and makes sure the value used to index the array which is
provided by userspace via netlink is checked to avoid out of
bound access.

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

1 files changed, 5 insertions, 0 deletions

diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 1fba6439fc57..fc920f63452b 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c
@@ -493,6 +493,11 @@ static int rtm_to_fib_config(struct sk_buff *skb, struct nlmsghdr *nlh,
         cfg->fc_nlinfo.pid = NETLINK_CB(skb).pid;
         cfg->fc_nlinfo.nlh = nlh;
 
+        if (cfg->fc_type > RTN_MAX) {
+                err = -EINVAL;
+                goto errout;
+        }
+
         nlmsg_for_each_attr(attr, nlh, sizeof(struct rtmsg), remaining) {
                 switch (attr->nla_type) {
                 case RTA_DST: