From: Phil Sutter <phil@xxxxxx>
If a requested extension exists as module and is not loaded,
ebt_check_match() might accidentally use an NFPROTO_UNSPEC one with same
name and fail.
Reproduced with limit match: Given xt_limit and ebt_limit both built as
module, the following would fail:
modprobe xt_limit
ebtables -I INPUT --limit 1/s -j ACCEPT
The fix is to make ebt_check_match() distrust a found NFPROTO_UNSPEC
extension and retry after requesting an appropriate module.
Cc: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Phil Sutter <phil@xxxxxx>
Acked-by: Florian Westphal <fw@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/bridge/netfilter/ebtables.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 8570bc7..5a61f35 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -370,7 +370,11 @@ ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par,
left - sizeof(struct ebt_entry_match) < m->match_size)
return -EINVAL;
- match = xt_request_find_match(NFPROTO_BRIDGE, m->u.name, 0);
+ match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
+ if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) {
+ request_module("ebt_%s", m->u.name);
+ match = xt_find_match(NFPROTO_BRIDGE, m->u.name, 0);
+ }
if (IS_ERR(match))
return PTR_ERR(match);
m->u.match = match;
--
2.1.4
--
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