netlink: Do not subscribe to non-existent groups

Make ABI more strict about subscribing to group > ngroups.
Code doesn't check for that and it looks bogus.
(one can subscribe to non-existing group)
Still, it's possible to bind() to all possible groups with (-1)

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dmitry Safonov 2018-07-27 16:54:44 +01:00 committed by David S. Miller
parent 9939a46d90
commit 7acf9d4237

View File

@ -1008,6 +1008,7 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
if (err)
return err;
}
groups &= (1UL << nlk->ngroups) - 1;
bound = nlk->bound;
if (bound) {