Commit 259d8c1e authored by Dan Williams's avatar Dan Williams Committed by Thomas Gleixner
Browse files

nl80211: Sanitize array index in parse_txq_params



Wireless drivers rely on parse_txq_params to validate that txq_params->ac
is less than NL80211_NUM_ACS by the time the low-level driver's ->conf_tx()
handler is called. Use a new helper, array_index_nospec(), to sanitize
txq_params->ac with respect to speculation. I.e. ensure that any
speculation into ->conf_tx() handlers is done with a value of
txq_params->ac that is within the bounds of [0, NL80211_NUM_ACS).

Reported-by: default avatarChristian Lamparter <chunkeey@gmail.com>
Reported-by: default avatarElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: default avatarDan Williams <dan.j.williams@intel.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarJohannes Berg <johannes@sipsolutions.net>
Cc: linux-arch@vger.kernel.org
Cc: kernel-hardening@lists.openwall.com
Cc: gregkh@linuxfoundation.org
Cc: linux-wireless@vger.kernel.org
Cc: torvalds@linux-foundation.org
Cc: "David S. Miller" <davem@davemloft.net>
Cc: alan@linux.intel.com
Link: https://lkml.kernel.org/r/151727419584.33451.7700736761686184303.stgit@dwillia2-desk3.amr.corp.intel.com
parent 56c30ba7
......@@ -16,6 +16,7 @@
#include <linux/nl80211.h>
#include <linux/rtnetlink.h>
#include <linux/netlink.h>
#include <linux/nospec.h>
#include <linux/etherdevice.h>
#include <net/net_namespace.h>
#include <net/genetlink.h>
......@@ -2056,20 +2057,22 @@ static const struct nla_policy txq_params_policy[NL80211_TXQ_ATTR_MAX + 1] = {
static int parse_txq_params(struct nlattr *tb[],
struct ieee80211_txq_params *txq_params)
{
u8 ac;
if (!tb[NL80211_TXQ_ATTR_AC] || !tb[NL80211_TXQ_ATTR_TXOP] ||
!tb[NL80211_TXQ_ATTR_CWMIN] || !tb[NL80211_TXQ_ATTR_CWMAX] ||
!tb[NL80211_TXQ_ATTR_AIFS])
return -EINVAL;
txq_params->ac = nla_get_u8(tb[NL80211_TXQ_ATTR_AC]);
ac = nla_get_u8(tb[NL80211_TXQ_ATTR_AC]);
txq_params->txop = nla_get_u16(tb[NL80211_TXQ_ATTR_TXOP]);
txq_params->cwmin = nla_get_u16(tb[NL80211_TXQ_ATTR_CWMIN]);
txq_params->cwmax = nla_get_u16(tb[NL80211_TXQ_ATTR_CWMAX]);
txq_params->aifs = nla_get_u8(tb[NL80211_TXQ_ATTR_AIFS]);
if (txq_params->ac >= NL80211_NUM_ACS)
if (ac >= NL80211_NUM_ACS)
return -EINVAL;
txq_params->ac = array_index_nospec(ac, NL80211_NUM_ACS);
return 0;
}
......
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