From: Phil Sutter <phil@nwl.cc>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org, Florian Westphal <fw@strlen.de>
Subject: [PATCH] netfilter: ebtables: Fix extension lookup with identical name
Date: Tue, 12 Apr 2016 01:31:14 +0200 [thread overview]
Message-ID: <1460417474-8899-1-git-send-email-phil@nwl.cc> (raw)
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@strlen.de>
Signed-off-by: Phil Sutter <phil@nwl.cc>
---
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 8570bc7744c25..5a61f35412a05 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;
--
2.8.0
next reply other threads:[~2016-04-11 23:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-11 23:31 Phil Sutter [this message]
2016-04-11 23:36 ` [PATCH] netfilter: ebtables: Fix extension lookup with identical name Florian Westphal
2016-04-12 23:17 ` Pablo Neira Ayuso
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1460417474-8899-1-git-send-email-phil@nwl.cc \
--to=phil@nwl.cc \
--cc=fw@strlen.de \
--cc=netfilter-devel@vger.kernel.org \
--cc=pablo@netfilter.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).