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 7A4A93ACFEE; Mon, 5 May 2025 23:19:19 +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=1746487159; cv=none; b=g7kqKoOfy4i26TGMkcbMoXlvArGfby8qsOb7+97PqTvLpQLL+fwAJLgdwUcRohayHKA1VmazCSw5f8if1c6GqmhJ7ZTavTbilRy/kr5e2lOzMkJs+tsDG8mp2wvgDOVME0FWOKgGqU4xe8vKOpSsMCs14/TFMgJlxiOwZMY7Bwk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746487159; c=relaxed/simple; bh=sMwPyvXBpK7TDRml1p1f82FV+kXU0/d7luIOBrkuOvo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZxcgBYVK1nl1swXqcRCN7cNzbZr6ZyHM3g9Ql+X1xy9eaixaci+oGpDOPrjUixtzS0LR1rb+ZNMXBFSqNVDJc05J1rjRwat806V5q6dOhazy0nPbNWCSiwDXUtqkvE56xJR6gJii5rMhspREScLFV0rD8Q2ArWZAZj00Ga8i0Ao= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=pRGy9K5u; 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="pRGy9K5u" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 03607C4CEED; Mon, 5 May 2025 23:19:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746487159; bh=sMwPyvXBpK7TDRml1p1f82FV+kXU0/d7luIOBrkuOvo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pRGy9K5u6ds7DKD+JKsESg4l2M33LrhOps55WZ9POcP19NkjDudN1u3zVtToPsfXK ObCChZexZmCGUH28SMrfU7GiyPaQvW0VHJI0kSR0FEASLP5/HmaUY5nuQ/FYdFa8P7 n8RCmlesww6F6xkz2pq7G/NfW9avVpnc0gaHRkY9yiMYsKKbP/V1WSi4dq40g1VMfq 7s+K8wFvDJbLvPOXrP23ic2kvinbQ7R7lpMLbHGWV8pyXVnLWL/utUEbjLvte8Srag oegfl3nhnm1lKe+H28hiQ5ayyXVaTXsTPfMM276YhpoLNBOOeJ0ImjWO2BhGFfZoGW DNRt2onu3FZFg== 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 5.10 033/114] netfilter: conntrack: Bound nf_conntrack sysctl writes Date: Mon, 5 May 2025 19:16:56 -0400 Message-Id: <20250505231817.2697367-33-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505231817.2697367-1-sashal@kernel.org> References: <20250505231817.2697367-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.10.237 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 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