From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 293271DAC76; Thu, 1 Aug 2024 00:34:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722472492; cv=none; b=cMvJzWwaT/KTFgdorGXOX6QCjx+lI0MG1XTohUvbMbbzETF+G8MqCe9ckWGW7QUof/m7lEi9TBgddPR/WAI7jnGNCpY4MlNhDSi1FLgDstyI+q6tyiFZI/THkG8q5MxPtsxHTx50WqZFvhtjmah9pis0+POsSob4NFBnSI7+67w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1722472492; c=relaxed/simple; bh=n7vWZjyWV/GaxQtxgyPbyC5TObQk4ygvhVDuU6Al6Tc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=nBm4KGPlLyrp7Tdmu3YABc3HBxv5PO7xFrmD/7Oz7VZAh7mBCNEpHg2hjx3w4jNDUmr3glsbkeLTPQi5kaC6+r1TS9tZpk5SprnC7rx1X1i7mYexBh2KO0rhxPcuRa9gjiYUtpR/gfjP0+ZOBFOzAln4McTzwYZfLPwLnCOeD0A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jlOcyHhD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jlOcyHhD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A700CC4AF0E; Thu, 1 Aug 2024 00:34:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1722472491; bh=n7vWZjyWV/GaxQtxgyPbyC5TObQk4ygvhVDuU6Al6Tc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jlOcyHhDIjO4gtKQThMAiq89yUuy50IUU+spj2yVXKQWv2T1KrS2pmH0ScTp4kYFL Fa0hgvSL5FZdwSBiB2sE6f4+AqXWAoItZsMcCKLyazezKY6g5D6MlLf9N2FYKtkMl1 4cmPYYS87ZZUdK1KEFc27I/PYbkzE9JGFTetXhGhH0Q+K7fXY1uVJsGKGh6kDZ3ccm ZgBTAhAmIqEE7yxd5gk0mRAJnk343edRwINHH+CSNgnSrtDFbDgPC+32oydjMobNVC KFObBgKvyAi6dGr9FSWtehvzzDbEIgfO0caw9WuQu7VPNTp3HNm+kjExyTu69FyLee C8XyBioUTxYDA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Casey Schaufler , Konstantin Andreev , Sasha Levin , paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, linux-security-module@vger.kernel.org Subject: [PATCH AUTOSEL 5.15 28/47] smack: tcp: ipv4, fix incorrect labeling Date: Wed, 31 Jul 2024 20:31:18 -0400 Message-ID: <20240801003256.3937416-28-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240801003256.3937416-1-sashal@kernel.org> References: <20240801003256.3937416-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-security-module@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.15.164 Content-Transfer-Encoding: 8bit From: Casey Schaufler [ Upstream commit 2fe209d0ad2e2729f7e22b9b31a86cc3ff0db550 ] Currently, Smack mirrors the label of incoming tcp/ipv4 connections: when a label 'foo' connects to a label 'bar' with tcp/ipv4, 'foo' always gets 'foo' in returned ipv4 packets. So, 1) returned packets are incorrectly labeled ('foo' instead of 'bar') 2) 'bar' can write to 'foo' without being authorized to write. Here is a scenario how to see this: * Take two machines, let's call them C and S, with active Smack in the default state (no settings, no rules, no labeled hosts, only builtin labels) * At S, add Smack rule 'foo bar w' (labels 'foo' and 'bar' are instantiated at S at this moment) * At S, at label 'bar', launch a program that listens for incoming tcp/ipv4 connections * From C, at label 'foo', connect to the listener at S. (label 'foo' is instantiated at C at this moment) Connection succeedes and works. * Send some data in both directions. * Collect network traffic of this connection. All packets in both directions are labeled with the CIPSO of the label 'foo'. Hence, label 'bar' writes to 'foo' without being authorized, and even without ever being known at C. If anybody cares: exactly the same happens with DCCP. This behavior 1st manifested in release 2.6.29.4 (see Fixes below) and it looks unintentional. At least, no explanation was provided. I changed returned packes label into the 'bar', to bring it into line with the Smack documentation claims. Signed-off-by: Konstantin Andreev Signed-off-by: Casey Schaufler Signed-off-by: Sasha Levin --- security/smack/smack_lsm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index e9d2ef3deccd1..25c46b56fae8d 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -4225,7 +4225,7 @@ static int smack_inet_conn_request(const struct sock *sk, struct sk_buff *skb, rcu_read_unlock(); if (hskp == NULL) - rc = netlbl_req_setattr(req, &skp->smk_netlabel); + rc = netlbl_req_setattr(req, &ssp->smk_out->smk_netlabel); else netlbl_req_delattr(req); -- 2.43.0