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 B85FB1FF61E; Mon, 2 Jun 2025 14:33:31 +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=1748874811; cv=none; b=KnENASQ9mvfMzDqUzEWDRZGsdSyubjZsa5tYjl3liZk2fr/EuFLfAo6pzAQBEtmj9ranfy6SB72pm+/NtiVbQm71HX1dwL3yD5nJck7K6rVFIAAyevW1gCdiY0F1/jwICJrIpwQNcR+fLvyq9PXdeWpTSqg1u9pCjYrKLAN1DSY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748874811; c=relaxed/simple; bh=SpRFl/g0d8a0jpKqNn5rZ8pntFlTuJLubCYyTvh3/yE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=VTqkYs/Ha+5D0dPFfooqo8ROYzMGDRKJc8NPKIM2K8U3W+8+CH1acy2ev4+zFAZhM+1EmCfTQpRdU/QHL7Cuxe5xB2b+cd4xNCv39saQ2/Jecj1GabiWdY5pg8Jh+bnQCSSf7YowMwjQkCZYIG5hsOxRVJu9MwtPGtwLxFFPq04= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=tL+Qbbel; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="tL+Qbbel" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3BBFFC4CEEB; Mon, 2 Jun 2025 14:33:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748874811; bh=SpRFl/g0d8a0jpKqNn5rZ8pntFlTuJLubCYyTvh3/yE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tL+QbbeldbZfVX8b8Ao9DiBBgNXdgtQgKsAa9Ihk2OgYG/jCibRtdOShZ+rMkOjM5 mk6RhVEiAAUh8DjLPWI06uGrYYrWvGW3ZqONxQvnaOv94A1agMZWHPRd0AP0e74L/p 2RnqMs66/6Xufxu8zfGPrh1430uRvI0VytDnD5ss= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nicolas Bouchinet , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 5.4 112/204] netfilter: conntrack: Bound nf_conntrack sysctl writes Date: Mon, 2 Jun 2025 15:47:25 +0200 Message-ID: <20250602134300.061905517@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250602134255.449974357@linuxfoundation.org> References: <20250602134255.449974357@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ 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 1e3dbed9d7840..de330dffa0a28 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -608,7 +608,9 @@ 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", @@ -647,7 +649,9 @@ 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", @@ -926,7 +930,9 @@ 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