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 EB9D322A4F6; Mon, 2 Jun 2025 15:06:50 +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=1748876811; cv=none; b=WzdA9Xb4nLW5/UuvnMH1HyoxL+4yoi7zuJDLjWf5nwik7og94a+mLNpKAwgnZlK4ZSB5CMSYfYhwn6p56YABEARmO+zlpLmyzugtAbIamZ1J12+9dx16M0aJh6FfJ99/aF27tagFSwKCg9LB7EilaH2GVr1c0lWwYXLjviDrxqE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748876811; c=relaxed/simple; bh=Bchql/oSbJoFvKwpQYZo3RnM6YYe9szN8rLGOL5/UN4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pUA+OJydoWPRA7aFPur+npL7F9qQZeHIysbY/58OceSR1t4QtmwYsdO+3PQO4pCaQlQvwukxbRaDbGxveRaULuVubsnD2HPecpDcPELa49supLp69NzxfBvSRaIpZjEEmpvRY2dBDm9cU0ve4KVqlq7S7XYrHyqwJ5tdhHrG0wM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=sXvhsygr; 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="sXvhsygr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7504AC4CEEB; Mon, 2 Jun 2025 15:06:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748876810; bh=Bchql/oSbJoFvKwpQYZo3RnM6YYe9szN8rLGOL5/UN4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sXvhsygrozEWAUxkHryt2Gt9J+9YszXpShehnyQKRuJFJXb5C34E4npcyC8qKjHlL f1q9qAndjwgNYA21hcWiKfkZEKZItw+B8WeqWuwlrCZ/sOJunlSbjnxBN6RYg8r1Py TVrV1tt6jpPuVWOwqikGtjclPrctaMMrxXoE1G3M= 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 6.1 082/325] netfilter: conntrack: Bound nf_conntrack sysctl writes Date: Mon, 2 Jun 2025 15:45:58 +0200 Message-ID: <20250602134323.114747634@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250602134319.723650984@linuxfoundation.org> References: <20250602134319.723650984@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-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 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