[4/9] netfilter: ebtables: enforce CAP_NET_ADMIN

[Greg KH <gregkh@suse.de>]

2.6.31-stable review patch.  If anyone has any objections, please let us know.

------------------

From: Florian Westphal <fwestphal@astaro.com>

commit dce766af541f6605fa9889892c0280bab31c66ab upstream.

normal users are currently allowed to set/modify ebtables rules.
Restrict it to processes with CAP_NET_ADMIN.

Note that this cannot be reproduced with unmodified ebtables binary
because it uses SOCK_RAW.

Signed-off-by: Florian Westphal <fwestphal@astaro.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 net/bridge/netfilter/ebtables.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1405,6 +1405,9 @@ static int do_ebt_set_ctl(struct sock *s
 {
 	int ret;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	switch(cmd) {
 	case EBT_SO_SET_ENTRIES:
 		ret = do_replace(sock_net(sk), user, len);
@@ -1424,6 +1427,9 @@ static int do_ebt_get_ctl(struct sock *s
 	struct ebt_replace tmp;
 	struct ebt_table *t;
 
+	if (!capable(CAP_NET_ADMIN))
+		return -EPERM;
+
 	if (copy_from_user(&tmp, user, sizeof(tmp)))
 		return -EFAULT;