android_kernel_motorola_sm6225/net/ipv4/metrics.c
Eric Dumazet ef050cf5fb 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: 6cf9dfd3bd ("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>
2023-02-06 07:49:43 +01:00

57 lines
1.3 KiB
C

#include <linux/netlink.h>
#include <linux/nospec.h>
#include <linux/rtnetlink.h>
#include <linux/types.h>
#include <net/ip.h>
#include <net/net_namespace.h>
#include <net/tcp.h>
int ip_metrics_convert(struct net *net, struct nlattr *fc_mx, int fc_mx_len,
u32 *metrics)
{
bool ecn_ca = false;
struct nlattr *nla;
int remaining;
if (!fc_mx)
return 0;
nla_for_each_attr(nla, fc_mx, fc_mx_len, remaining) {
int type = nla_type(nla);
u32 val;
if (!type)
continue;
if (type > RTAX_MAX)
return -EINVAL;
type = array_index_nospec(type, RTAX_MAX + 1);
if (type == RTAX_CC_ALGO) {
char tmp[TCP_CA_NAME_MAX];
nla_strlcpy(tmp, nla, sizeof(tmp));
val = tcp_ca_get_key_by_name(net, tmp, &ecn_ca);
if (val == TCP_CA_UNSPEC)
return -EINVAL;
} else {
if (nla_len(nla) != sizeof(u32))
return -EINVAL;
val = nla_get_u32(nla);
}
if (type == RTAX_ADVMSS && val > 65535 - 40)
val = 65535 - 40;
if (type == RTAX_MTU && val > 65535 - 15)
val = 65535 - 15;
if (type == RTAX_HOPLIMIT && val > 255)
val = 255;
if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK))
return -EINVAL;
metrics[type - 1] = val;
}
if (ecn_ca)
metrics[RTAX_FEATURES - 1] |= DST_FEATURE_ECN_CA;
return 0;
}
EXPORT_SYMBOL_GPL(ip_metrics_convert);