libertas: Read buffer overflow

Several arrays were read before checking whether the index was within
bounds. ARRAY_SIZE() should be used to determine the size of arrays.

rates->rates has an arraysize of 1, so calling get_common_rates()
with a rates_size of MAX_RATES (14) was causing reads out of bounds.

tmp_size can increment at most to (ARRAY_SIZE(lbs_bg_rates) - 1) *
(*rates_size - 1), so that should be the number of elements of tmp[].

A goto can be eliminated: ret was already set upon its declaration.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This commit is contained in:
Roel Kluin 2009-07-28 12:05:00 +02:00 committed by John W. Linville
parent 430453fc2a
commit 57921c312e

View file

@ -1,6 +1,7 @@
/* Copyright (C) 2006, Red Hat, Inc. */
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/etherdevice.h>
#include <linux/ieee80211.h>
#include <linux/if_arp.h>
@ -43,21 +44,21 @@ static int get_common_rates(struct lbs_private *priv,
u16 *rates_size)
{
u8 *card_rates = lbs_bg_rates;
size_t num_card_rates = sizeof(lbs_bg_rates);
int ret = 0, i, j;
u8 tmp[30];
u8 tmp[(ARRAY_SIZE(lbs_bg_rates) - 1) * (*rates_size - 1)];
size_t tmp_size = 0;
/* For each rate in card_rates that exists in rate1, copy to tmp */
for (i = 0; card_rates[i] && (i < num_card_rates); i++) {
for (j = 0; rates[j] && (j < *rates_size); j++) {
for (i = 0; i < ARRAY_SIZE(lbs_bg_rates) && card_rates[i]; i++) {
for (j = 0; j < *rates_size && rates[j]; j++) {
if (rates[j] == card_rates[i])
tmp[tmp_size++] = card_rates[i];
}
}
lbs_deb_hex(LBS_DEB_JOIN, "AP rates ", rates, *rates_size);
lbs_deb_hex(LBS_DEB_JOIN, "card rates ", card_rates, num_card_rates);
lbs_deb_hex(LBS_DEB_JOIN, "card rates ", card_rates,
ARRAY_SIZE(lbs_bg_rates));
lbs_deb_hex(LBS_DEB_JOIN, "common rates", tmp, tmp_size);
lbs_deb_join("TX data rate 0x%02x\n", priv->cur_rate);
@ -69,10 +70,7 @@ static int get_common_rates(struct lbs_private *priv,
lbs_pr_alert("Previously set fixed data rate %#x isn't "
"compatible with the network.\n", priv->cur_rate);
ret = -1;
goto done;
}
ret = 0;
done:
memset(rates, 0, *rates_size);
*rates_size = min_t(int, tmp_size, *rates_size);
@ -322,7 +320,7 @@ static int lbs_associate(struct lbs_private *priv,
rates = (struct mrvl_ie_rates_param_set *) pos;
rates->header.type = cpu_to_le16(TLV_TYPE_RATES);
memcpy(&rates->rates, &bss->rates, MAX_RATES);
tmplen = MAX_RATES;
tmplen = min_t(u16, ARRAY_SIZE(rates->rates), MAX_RATES);
if (get_common_rates(priv, rates->rates, &tmplen)) {
ret = -1;
goto done;
@ -598,7 +596,7 @@ static int lbs_adhoc_join(struct lbs_private *priv,
/* Copy Data rates from the rates recorded in scan response */
memset(cmd.bss.rates, 0, sizeof(cmd.bss.rates));
ratesize = min_t(u16, sizeof(cmd.bss.rates), MAX_RATES);
ratesize = min_t(u16, ARRAY_SIZE(cmd.bss.rates), MAX_RATES);
memcpy(cmd.bss.rates, bss->rates, ratesize);
if (get_common_rates(priv, cmd.bss.rates, &ratesize)) {
lbs_deb_join("ADHOC_JOIN: get_common_rates returned error.\n");