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 94CE02D81B6; Mon, 5 May 2025 22:21:07 +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=1746483667; cv=none; b=rYMAc6Iac8LXapqA33izGcPjBBEq0CKPb4Z9ldr4ZczLTLk66emIpRniaNeWAsGsZXMpVgv9hNp4MR0CpqBj1c3NQImRKqWqPg7R0jWZ38lDEi67lmAr0TkAqU1LBP+CLJJFnoxEf3EKorfJg9JdLPyGSPP2ZN7gn0luHfF2I70= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746483667; c=relaxed/simple; bh=wJ4ABvpT6YEmVF11t4tMp/Em1QVXjSiQC/jrI5UWAAI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=EIpGegyes5VCaFOI11AXObQoCfjo7FA49OqO67SlQyUq70BmKHPDpOfyvLSRqfnuxJAyK6s9yT2HALNmtG/QlvFA9iCSUykFDNn9e+odMcoYknCSxbTVL3ibpTg9Yq2nxd8OEuvdSJzdhRClwwB6JpY1j2TS57fIGuE2YSh3cR4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FsL9qfGt; 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="FsL9qfGt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 186FDC4CEEE; Mon, 5 May 2025 22:21:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746483667; bh=wJ4ABvpT6YEmVF11t4tMp/Em1QVXjSiQC/jrI5UWAAI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FsL9qfGt2LLcPK3SXZzT+kPS//tyntZ/8K0R5iUAUHniqXnhMTLSO89nsG+z9ge6E Kx/VFyKYf1ualLDCqyMKyjor2ZwdXt1njqwb03NO6H5pGI5L8W7c6gNM/gQ2ytHTin QJZiCdNVPsjUdMaLfY9qJXXerKMxvOmUDeqxTnxJVwovc6mWxAlKEw4Y7VuYmFc/Ju 34Q8rtJjVKN4PA2G0y4Aczgg9P4l3pA0tFtezsN1dYq/JDzOCUeDbiOdDhD4HvnD7D ZLzNJNt2EkE4oLyckmagCGd3z5lP2oU4QnGU+48OZmRs5r2O3VjjaMcj4MuqRf+sTD ppNWqSi9rIrjQ== 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 6.14 169/642] netfilter: conntrack: Bound nf_conntrack sysctl writes Date: Mon, 5 May 2025 18:06:25 -0400 Message-Id: <20250505221419.2672473-169-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505221419.2672473-1-sashal@kernel.org> References: <20250505221419.2672473-1-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 6.14.5 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 502cf10aab41d..2f666751c7e7c 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -618,7 +618,9 @@ 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", @@ -654,7 +656,9 @@ 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", @@ -947,7 +951,9 @@ 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