Revert "netfilter: ensure number of counters is >0 in do_replace()"

commit d26e2c9ffa385dd1b646f43c1397ba12af9ed431 upstream.

This partially reverts commit 1086bbe97a07 ("netfilter: ensure number of
counters is >0 in do_replace()") in net/bridge/netfilter/ebtables.c.

Setting rules with ebtables does not work any more with 1086bbe97a07 place.

There is an error message and no rules set in the end.

e.g.

~# ebtables -t nat -A POSTROUTING --src 12:34:56:78:9a:bc -j DROP
Unable to update the kernel. Two possible causes:
1. Multiple ebtables programs were executing simultaneously. The ebtables
   userspace tool doesn't by default support multiple ebtables programs
running

Reverting the ebtables part of 1086bbe97a07 makes this work again.

Signed-off-by: Bernhard Thaler <bernhard.thaler@wvnet.at>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
[sw0312.kim: cherry-pick from linux-3.10.y to apply CVE]
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Change-Id: I01b33f065e82745e98b865b630344539855e3866

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 8d60948..6651a77 100644 (file)
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1105,8 +1105,6 @@ static int do_replace(struct net *net, const void __user *user,
                return -ENOMEM;
        if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
                return -ENOMEM;
-       if (tmp.num_counters == 0)
-               return -EINVAL;
 
        tmp.name[sizeof(tmp.name) - 1] = 0;
 
@@ -2152,8 +2150,6 @@ static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl,
                return -ENOMEM;
        if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter))
                return -ENOMEM;
-       if (tmp.num_counters == 0)
-               return -EINVAL;
 
        memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry));