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 7AD942ECFFF; Mon, 5 May 2025 23:08:29 +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=1746486509; cv=none; b=KWkzIij0tqO0c4cM8rN8FfrkvCNhNttrXEmdp2ssw7Is7xVtAYRIu0tTxoh/9eN1vps15ddmD2eTHRMb55IbOqEQ5b4rAY/LJrikqPhKcbuGA7QNNwGAFuJd4zO04/HfOGPqavhpiHKBkzLbKeOpPHW673MtzUZjN9r7Zs7Pq7s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746486509; c=relaxed/simple; bh=CvZy6PV0XzT2rBkLKJjXMgmKuMb0AlaAod2uUWCGLZI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=GeLCtagydI2GajITCm4E427UBgpsfvbszclTvPzDZUAA2QAH4frKV+WUn9RT9aKr5m8grpa17i3ubglZQUN3jRQGIpXCvNeQY1WQCoBOnfSoXN2Zo+Tlv6SXZwR4Xi3UtHUFbMFcafAXkTV28WOInmve8n7kimjBFLNVickujEA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=T1TNo7HE; 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="T1TNo7HE" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2D2DC4CEEE; Mon, 5 May 2025 23:08:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746486509; bh=CvZy6PV0XzT2rBkLKJjXMgmKuMb0AlaAod2uUWCGLZI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=T1TNo7HEpx+EQd9nq/aUfww8RrFxtayIvh17F7I6oPNG9PgMdI/YRIp+COhCdzY4u ZDukmeE84BLKT7iYHZJMczwow/1t2B57QqSl3ZBGL9gF1Gg9Ab52FKPqugezeSX5Yk aPdRi0cmbJkaZJtEM1FF7+eZi4+sgchmrlmohOjJ2QbyIMxAO7AIIqR7dqz8zYRF/o scwUXhkG39R3GbfFBdmKSM2+rF9hU2AhjA2n+Ydbl5c67jSH54AcTei2UbOiA1euzC L1EfLPwQ+QoES6viDPukLqk7Sl2Ae9uAibI32BMkC5ams56jcGlSyPbeM53Htwi+8B kVput2ixomjBA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Nicolas Bouchinet , Pablo Neira Ayuso , Sasha Levin , kadlec@netfilter.org, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 6.1 067/212] netfilter: conntrack: Bound nf_conntrack sysctl writes Date: Mon, 5 May 2025 19:03:59 -0400 Message-Id: <20250505230624.2692522-67-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505230624.2692522-1-sashal@kernel.org> References: <20250505230624.2692522-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.136 Content-Transfer-Encoding: 8bit From: Nicolas Bouchinet [ Upstream commit 8b6861390ffee6b8ed78b9395e3776c16fec6579 ] nf_conntrack_max and nf_conntrack_expect_max sysctls were authorized to be written any negative value, which would then be stored in the unsigned int variables nf_conntrack_max and nf_ct_expect_max variables. While the do_proc_dointvec_conv function is supposed to limit writing handled by proc_dointvec proc_handler to INT_MAX. Such a negative value being written in an unsigned int leads to a very high value, exceeding this limit. Moreover, the nf_conntrack_expect_max sysctl documentation specifies the minimum value is 1. The proc_handlers have thus been updated to proc_dointvec_minmax in order to specify the following write bounds : * Bound nf_conntrack_max sysctl writings between SYSCTL_ZERO and SYSCTL_INT_MAX. * Bound nf_conntrack_expect_max sysctl writings between SYSCTL_ONE and SYSCTL_INT_MAX as defined in the sysctl documentation. With this patch applied, sysctl writes outside the defined in the bound will thus lead to a write error : ``` sysctl -w net.netfilter.nf_conntrack_expect_max=-1 sysctl: setting key "net.netfilter.nf_conntrack_expect_max": Invalid argument ``` Signed-off-by: Nicolas Bouchinet Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nf_conntrack_standalone.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/net/netfilter/nf_conntrack_standalone.c b/net/netfilter/nf_conntrack_standalone.c index 52245dbfae311..c333132e20799 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -631,7 +631,9 @@ static struct ctl_table nf_ct_sysctl_table[] = { .data = &nf_conntrack_max, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_INT_MAX, }, [NF_SYSCTL_CT_COUNT] = { .procname = "nf_conntrack_count", @@ -667,7 +669,9 @@ static struct ctl_table nf_ct_sysctl_table[] = { .data = &nf_ct_expect_max, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ONE, + .extra2 = SYSCTL_INT_MAX, }, [NF_SYSCTL_CT_ACCT] = { .procname = "nf_conntrack_acct", @@ -970,7 +974,9 @@ static struct ctl_table nf_ct_netfilter_table[] = { .data = &nf_conntrack_max, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_INT_MAX, }, { } }; -- 2.39.5