netfilter: nfnetlink: relax strict multicast group check from netlink_bind

commit 62924af247e95de7041a6d6f2d06cdd05152e2dc upstream.

Relax the checking that was introduced in 97840cb ("netfilter:
nfnetlink: fix insufficient validation in nfnetlink_bind") when the
subscription bitmask is used. Existing userspace code code may request
to listen to all of the existing netlink groups by setting an all to one
subscription group bitmask. Netlink already validates subscription via
setsockopt() for us.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index c6619d4bcc32c7a5d8a3a1034ebfadb3cc7aa85c..1aa7049c93f5f4341dad5a83fd568b167936e306 100644 (file)
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -470,7 +470,7 @@ static int nfnetlink_bind(int group)
        int type;
 
        if (group <= NFNLGRP_NONE || group > NFNLGRP_MAX)
-               return -EINVAL;
+               return 0;
 
        type = nfnl_group2type[group];