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 DA8A6227BA4; Mon, 2 Jun 2025 14:44:49 +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=1748875489; cv=none; b=A3QD7I5f3Q53v6QfB/Fj5EEFetJPoRipuhyWuCI3w38ee0b0rQhUE4N7y4tYYl7VNnnzxPN3IU5+GTB9CF0c9clgEo0+zIF5YvP19LQMJtN5JlVREiYrPeyFvJh3gVQOMXz0SHt4VqVaNSyxln7kRNIRDo+BFJCNDtSQL2Qw3DQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748875489; c=relaxed/simple; bh=VXpBokGVLs5g2KT+b3yzLvFYwvtGlgk8pP31jGgZ3tw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=A2piA6/h925xKTBdsZw6cFygBoFWpBvhDyq+9gtASykXDPBBWpDDKYpcOSbqjR5iXa6rS8jxaHCSmqB8WnvtAiw+rg+7QIH0+sSCC7BzRE8qndc9+lbf4hzB4dqUowTNZ9P5jx5sxCsGftSQZyG4vraxqgvF2wUvByvM/WgHDd8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=e8aiQH7k; 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="e8aiQH7k" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 48425C4CEEB; Mon, 2 Jun 2025 14:44:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748875489; bh=VXpBokGVLs5g2KT+b3yzLvFYwvtGlgk8pP31jGgZ3tw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=e8aiQH7kX2u4hF0rq/juoHLPa+F2QIfAihCNOCMghHik24HhpZ65zYZnu4QXWa/ZX o8Lqt1Q6C+J62KXw+orKYykh+CohuLpWXBvU/EFu4CUZ55g3mui2VX/JL0eUH8kBqd WMBe3zb4M/TKjrxZSAMgXnjLbFEi15ded7osPe6o= 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 5.10 150/270] netfilter: conntrack: Bound nf_conntrack sysctl writes Date: Mon, 2 Jun 2025 15:47:15 +0200 Message-ID: <20250602134313.352048326@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250602134307.195171844@linuxfoundation.org> References: <20250602134307.195171844@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 5.10-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 8498bf27a3531..abf558868db11 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -613,7 +613,9 @@ 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", @@ -652,7 +654,9 @@ 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", @@ -931,7 +935,9 @@ 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