[4/9] netfilter: ebtables: enforce CAP_NET_ADMIN

From: Greg KH
Date: Thu Jan 14 2010 - 17:53:30 EST


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

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

From: Florian Westphal <fwestphal@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Patrick McHardy <kaber@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
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;



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