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authorJohannes Berg <johannes.berg@intel.com>2019-02-06 14:17:14 +0300
committerJohannes Berg <johannes.berg@intel.com>2019-02-11 17:50:56 +0300
commit1fc9b7253382ce1a83d9a3e63e88d656eb63f263 (patch)
tree75a2d5946ca8dac7115b3182f858b7866b591eeb /net/wireless/util.c
parentff1bab1ba19165d4402447dd39abae9e21880ebf (diff)
downloadlinux-1fc9b7253382ce1a83d9a3e63e88d656eb63f263.tar.xz
cfg80211: prevent speculation on cfg80211_classify8021d() return
It's possible that the caller of cfg80211_classify8021d() uses the value to index an array, like mac80211 in ieee80211_downgrade_queue(). Prevent speculation on the return value. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Luca Coelho <luciano.coelho@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net/wireless/util.c')
-rw-r--r--net/wireless/util.c35
1 files changed, 24 insertions, 11 deletions
diff --git a/net/wireless/util.c b/net/wireless/util.c
index cd48cdd582c0..ec30e3732c7b 100644
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -5,7 +5,7 @@
* Copyright 2007-2009 Johannes Berg <johannes@sipsolutions.net>
* Copyright 2013-2014 Intel Mobile Communications GmbH
* Copyright 2017 Intel Deutschland GmbH
- * Copyright (C) 2018 Intel Corporation
+ * Copyright (C) 2018-2019 Intel Corporation
*/
#include <linux/export.h>
#include <linux/bitops.h>
@@ -19,6 +19,7 @@
#include <linux/mpls.h>
#include <linux/gcd.h>
#include <linux/bitfield.h>
+#include <linux/nospec.h>
#include "core.h"
#include "rdev-ops.h"
@@ -715,20 +716,25 @@ unsigned int cfg80211_classify8021d(struct sk_buff *skb,
{
unsigned int dscp;
unsigned char vlan_priority;
+ unsigned int ret;
/* skb->priority values from 256->263 are magic values to
* directly indicate a specific 802.1d priority. This is used
* to allow 802.1d priority to be passed directly in from VLAN
* tags, etc.
*/
- if (skb->priority >= 256 && skb->priority <= 263)
- return skb->priority - 256;
+ if (skb->priority >= 256 && skb->priority <= 263) {
+ ret = skb->priority - 256;
+ goto out;
+ }
if (skb_vlan_tag_present(skb)) {
vlan_priority = (skb_vlan_tag_get(skb) & VLAN_PRIO_MASK)
>> VLAN_PRIO_SHIFT;
- if (vlan_priority > 0)
- return vlan_priority;
+ if (vlan_priority > 0) {
+ ret = vlan_priority;
+ goto out;
+ }
}
switch (skb->protocol) {
@@ -747,8 +753,9 @@ unsigned int cfg80211_classify8021d(struct sk_buff *skb,
if (!mpls)
return 0;
- return (ntohl(mpls->entry) & MPLS_LS_TC_MASK)
+ ret = (ntohl(mpls->entry) & MPLS_LS_TC_MASK)
>> MPLS_LS_TC_SHIFT;
+ goto out;
}
case htons(ETH_P_80221):
/* 802.21 is always network control traffic */
@@ -761,18 +768,24 @@ unsigned int cfg80211_classify8021d(struct sk_buff *skb,
unsigned int i, tmp_dscp = dscp >> 2;
for (i = 0; i < qos_map->num_des; i++) {
- if (tmp_dscp == qos_map->dscp_exception[i].dscp)
- return qos_map->dscp_exception[i].up;
+ if (tmp_dscp == qos_map->dscp_exception[i].dscp) {
+ ret = qos_map->dscp_exception[i].up;
+ goto out;
+ }
}
for (i = 0; i < 8; i++) {
if (tmp_dscp >= qos_map->up[i].low &&
- tmp_dscp <= qos_map->up[i].high)
- return i;
+ tmp_dscp <= qos_map->up[i].high) {
+ ret = i;
+ goto out;
+ }
}
}
- return dscp >> 5;
+ ret = dscp >> 5;
+out:
+ return array_index_nospec(ret, IEEE80211_NUM_TIDS);
}
EXPORT_SYMBOL(cfg80211_classify8021d);