From: Eric Dumazet <edumazet@google.com>
Date: Fri, 20 Jan 2023 13:30:40 +0000 (+0000)
Subject: ipv4: prevent potential spectre v1 gadget in ip_metrics_convert()
X-Git-Tag: baikal/aarch64/sdk5.9~46
X-Git-Url: https://git.baikalelectronics.ru/sdk/?a=commitdiff_plain;h=54267467b4bb1615a3a62cabe147daebd2cd5b29;p=kernel.git

ipv4: prevent potential spectre v1 gadget in ip_metrics_convert()

[ Upstream commit 1d1d63b612801b3f0a39b7d4467cad0abd60e5c8 ]

if (!type)
		continue;
	if (type > RTAX_MAX)
		return -EINVAL;
	...
	metrics[type - 1] = val;

@type being used as an array index, we need to prevent
cpu speculation or risk leaking kernel memory content.

Fixes: cd8f53800078 ("net: fib: move metrics parsing to a helper")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230120133040.3623463-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/net/ipv4/metrics.c b/net/ipv4/metrics.c
index 3205d5f7c8c94..4966ac2aaf87d 100644
--- a/net/ipv4/metrics.c
+++ b/net/ipv4/metrics.c
@@ -1,5 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 #include <linux/netlink.h>
+#include <linux/nospec.h>
 #include <linux/rtnetlink.h>
 #include <linux/types.h>
 #include <net/ip.h>
@@ -28,6 +29,7 @@ static int ip_metrics_convert(struct net *net, struct nlattr *fc_mx,
 			return -EINVAL;
 		}
 
+		type = array_index_nospec(type, RTAX_MAX + 1);
 		if (type == RTAX_CC_ALGO) {
 			char tmp[TCP_CA_NAME_MAX];