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 B5A7F27FD5C; Mon, 5 May 2025 22:59:15 +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=1746485955; cv=none; b=jmnqAf6brvhHnA4WZ6EFRBi3Lo4tKwTnk4cflkLFCy+yfLvfR8dC5XMtDg+qTo+kpLBK5k0MkYTGVtVc7xYLRjI8+U0rWT+Q3N4rqa6b91X3vRn6GX02ABf0ICX+SdoUi/jsZhzbl8oY8V3tJX58ksFsj85qzryFCQnw2kEnGjA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746485955; c=relaxed/simple; bh=5DgwbfDE6r7BMf4An3ZJ7JUYII7xsZ0Zmz9zc4GFmCU=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=pdqOnlp9beyj8IKrty8n0k2V74C2i9styHd5urnDc4A8xP2M3XTAKI/93qro+3OmvEwlHXGxcKEOlEBqxPXuo6lWIrPcQj81FxorgZYg4RwqkwZsyzG9zUSLdDB5dTxOB8cHOVJyFPUjljpG6r14uQ4PipiF/3oe3BBUlhOCEsQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ptLiZzDa; 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="ptLiZzDa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3BB24C4CEE4; Mon, 5 May 2025 22:59:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746485955; bh=5DgwbfDE6r7BMf4An3ZJ7JUYII7xsZ0Zmz9zc4GFmCU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ptLiZzDa4mRzkoM/ZGLJonWs2douKxSAnzcjnnuHSXu3atTY64L5wwj89qn444YVQ B+itgt1D54mo4IAvZLW0U9yFU+DragPVnFslc0jDdaWTmgcmsvXClgdPeLdY77Ofqp aBzCJ9Xow9IRX+jj4Ns7TgZ6lrE8rQHVX9ydQIU1mCBeXsWtuqmz6gY+b0jLytlrpR C550wdKNRyfV2X5Saw9Y+dzw6ZKpuljWmlDUy42zEeJAFUZBwmTNbAPV40Tq2yNoAx F99XzAD8QH5Oi0p08MSWA/SL8gWmgugQ5Wx6jMQcVBeXcK6ewApYxzgJnW16n/MkyQ NiuCM8Qz862rw== 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 6.6 084/294] netfilter: conntrack: Bound nf_conntrack sysctl writes Date: Mon, 5 May 2025 18:53:04 -0400 Message-Id: <20250505225634.2688578-84-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505225634.2688578-1-sashal@kernel.org> References: <20250505225634.2688578-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.6.89 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 559665467b04d..1d5de1d9f008d 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -621,7 +621,9 @@ 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", @@ -657,7 +659,9 @@ 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", @@ -951,7 +955,9 @@ 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