Commit 1d1d63b6 authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

ipv4: prevent potential spectre v1 gadget in ip_metrics_convert() 



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: default avatarEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20230120133040.3623463-1-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent d6ab640c

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>
@@ -25,6 +26,7 @@ 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];