Commit 746db9ec authored Jan 20, 2023 by Eric Dumazet Committed by Greg Kroah-Hartman Feb 06, 2023

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: 6cf9dfd3 ("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>

parent 4cde1d2f

net/ipv4/metrics.c

+2 −0

Original line number	Diff line number	Diff line
		// 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];