netfilter: ebtables: enforce CAP_NET_ADMIN
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>
Cc: stable@kernel.org
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index bd1c654..0b7f262 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1406,6 +1406,9 @@
{
int ret;
+ if (!capable(CAP_NET_ADMIN))
+ return -EPERM;
+
switch(cmd) {
case EBT_SO_SET_ENTRIES:
ret = do_replace(sock_net(sk), user, len);
@@ -1425,6 +1428,9 @@
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;