linux-kernel - [PATCH 4.14 203/343] netfilter: ebtables: CONFIG_COMPAT: reject trailing data after last rule

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20200124092946.701793857@linuxfoundation.org>
Date:   Fri, 24 Jan 2020 10:30:21 +0100
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org,
        Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>,
        Florian Westphal <fw@...len.de>,
        Pablo Neira Ayuso <pablo@...filter.org>,
        Sasha Levin <sashal@...nel.org>
Subject: [PATCH 4.14 203/343] netfilter: ebtables: CONFIG_COMPAT: reject trailing data after last rule

From: Florian Westphal <fw@...len.de>

[ Upstream commit 680f6af5337c98d116e4f127cea7845339dba8da ]

If userspace provides a rule blob with trailing data after last target,
we trigger a splat, then convert ruleset to 64bit format (with trailing
data), then pass that to do_replace_finish() which then returns -EINVAL.

Erroring out right away avoids the splat plus unneeded translation and
error unwind.

Fixes: 81e675c227ec ("netfilter: ebtables: add CONFIG_COMPAT support")
Reported-by: Tetsuo Handa <penguin-kernel@...ove.sakura.ne.jp>
Signed-off-by: Florian Westphal <fw@...len.de>
Signed-off-by: Pablo Neira Ayuso <pablo@...filter.org>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
 net/bridge/netfilter/ebtables.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index 35a670ec90775..a1834ad7422ce 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -2164,7 +2164,9 @@ static int compat_copy_entries(unsigned char *data, unsigned int size_user,
 	if (ret < 0)
 		return ret;
 
-	WARN_ON(size_remaining);
+	if (size_remaining)
+		return -EINVAL;
+
 	return state->buf_kern_offset;
 }
 
-- 
2.20.1