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 B98D32F3A8E; Mon, 5 May 2025 23:14:53 +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=1746486893; cv=none; b=IbbWKS6qCjoklZflWKdcKPhuy5GSt1AmclodG1s//d2026vWISdkazQZgXspJJnAP7nXCRCnJ+IqD0rs9q+PEfHcm4jTN4YWlrWOTdX5FJakpJ/xh4P2l+T/dLCsifp75eJB2ddDELEz4L3INvpmFylyAqhUHoGCRMQH3YdtiEU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746486893; c=relaxed/simple; bh=k7U5ZkxStIoJ2OWerJ26c5Smu0n+lwx1QJs5hxu2pMw=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=P+Ipl2+LZXb6bH7V0sIYwkl8qBVqpmo5fTSGzuNq3cyzTOhnRZcm2oFPP1cA+VaRj8ckaHH3+OOj5+V7uwowHycdqH3G4XNj63B8Wdq7Ng3wXSZV9DP0P9DJsS44CwAqznj8tJuGnmIsVB6PTgJEsQnvcp5h+U8k5VPnH6g+kmI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kK2k9FLT; 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="kK2k9FLT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C44A7C4CEE4; Mon, 5 May 2025 23:14:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746486893; bh=k7U5ZkxStIoJ2OWerJ26c5Smu0n+lwx1QJs5hxu2pMw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kK2k9FLTxsNu2Rrx6XwooisGfWpTcO3pXFZSfSe9Zj4CSxwUSnfYmX4MCDNyMf9no IDvjQUevSBVe1wDv+qwNJ2cY19EirBMCJxyO83XvqtTFRUol+12FatHPJ59XhqL3a3 XNjRVvqPsTqDHwG99lTK0I/mNleohAHGoROUsNlcDWK4tKmfEWu2n/EBEEw9ShjJWd sNr0UYSGHfJxTqaPEnYXI6CFprUJlumeCkHrqEe0OVSqzO9TRJYYSIL81/hX7sM82X sFMlihL5yexdvmBeO1+IBHsoKeFxLKbPC5quHsxaU4m0Ic8kNmuZI6cG4Lvszh5LEV IvzqiGkO/p2Ew== 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 5.15 048/153] netfilter: conntrack: Bound nf_conntrack sysctl writes Date: Mon, 5 May 2025 19:11:35 -0400 Message-Id: <20250505231320.2695319-48-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505231320.2695319-1-sashal@kernel.org> References: <20250505231320.2695319-1-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 5.15.181 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 7515705583bcf..770590041c549 100644 --- a/net/netfilter/nf_conntrack_standalone.c +++ b/net/netfilter/nf_conntrack_standalone.c @@ -629,7 +629,9 @@ 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", @@ -665,7 +667,9 @@ 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", @@ -976,7 +980,9 @@ 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