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 2F27F3BB681; Mon, 5 May 2025 23:22:34 +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=1746487355; cv=none; b=rFZqYBIk407A7dg5V9DlSKDOkC/TYlXBp/OLcEgINJe1bI++WkLQPXZ6RPMwdDjquw8kB925y3O+T/0EPzlXhE3gsRvt7aYGO923QJjh9+1fwW9TgI/hKxR9mGwMDAawQyRUlJLKFExBWIAeo8q8/MZvtZvRzkx4q+vmCPj2TMQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746487355; c=relaxed/simple; bh=33fKuR8xSXXrYYpGa+BSRpBI1AmNXITApsh+Wb6LxWI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=HsSjveUZ32yspzLN5j2UN0xCxyjmsPqlwxsxPYayXcIn03XgBuUwamKcvn8yE3CS0CD87rxzUMu7EkM+VF4OZSMUzJab7N8fNhk2DXomtw4eE/I69KLXPjIqs9jYDeGlHIRhHnTWwqtvq9FDGwstA4dg3k2oTp3XIkM39IJTaI0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=CWib3jlR; 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="CWib3jlR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 87B68C4CEF2; Mon, 5 May 2025 23:22:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746487354; bh=33fKuR8xSXXrYYpGa+BSRpBI1AmNXITApsh+Wb6LxWI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CWib3jlRTj8QtOwbPvpLNmL+yBmN+XTpLkFZNCP9nBMn2V0vNdso5e65bM3wEacrR 177ssZdoXLxDgXCtWuFrASIld4TFaRF9UmK8TRXj9otveIl1w5pE8dhvdXZLsGdvrG 4Lr6Rp8yZZwxVo66uLCebUrf9c81ahlDz/dYWRgkHW9RnSbs221yCNcMHD0vrZc80/ vsqhVNQXW5lin+WCHiaCYyV9UFGTlm16PuS057lLCuwcOOVO/t6yDBh4Iwt3keU/jz 3B5YLSBJorixAS9pF9UwraDbO0in76792tRvNbjXMff+OjJA0GBYFlzGdC5TVq7KIQ usR2uXxV/hTJQ== 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 5.4 25/79] netfilter: conntrack: Bound nf_conntrack sysctl writes Date: Mon, 5 May 2025 19:20:57 -0400 Message-Id: <20250505232151.2698893-25-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505232151.2698893-1-sashal@kernel.org> References: <20250505232151.2698893-1-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 5.4.293 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 1e3dbed9d7840..de330dffa0a28 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -608,7 +608,9 @@ 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", @@ -647,7 +649,9 @@ 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", @@ -926,7 +930,9 @@ 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