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linux-next/net/wireless/wext-sme.c
Will Deacon 4ac2813cc8 cfg80211: wext: avoid copying malformed SSIDs
Ensure the SSID element is bounds-checked prior to invoking memcpy()
with its length field, when copying to userspace.

Cc: <stable@vger.kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Reported-by: Nicolas Waisman <nico@semmle.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20191004095132.15777-2-will@kernel.org
[adjust commit log a bit]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-10-04 14:04:08 +02:00

396 lines
8.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* cfg80211 wext compat for managed mode.
*
* Copyright 2009 Johannes Berg <johannes@sipsolutions.net>
* Copyright (C) 2009 Intel Corporation. All rights reserved.
*/
#include <linux/export.h>
#include <linux/etherdevice.h>
#include <linux/if_arp.h>
#include <linux/slab.h>
#include <net/cfg80211.h>
#include <net/cfg80211-wext.h>
#include "wext-compat.h"
#include "nl80211.h"
int cfg80211_mgd_wext_connect(struct cfg80211_registered_device *rdev,
struct wireless_dev *wdev)
{
struct cfg80211_cached_keys *ck = NULL;
const u8 *prev_bssid = NULL;
int err, i;
ASSERT_RTNL();
ASSERT_WDEV_LOCK(wdev);
if (!netif_running(wdev->netdev))
return 0;
wdev->wext.connect.ie = wdev->wext.ie;
wdev->wext.connect.ie_len = wdev->wext.ie_len;
/* Use default background scan period */
wdev->wext.connect.bg_scan_period = -1;
if (wdev->wext.keys) {
wdev->wext.keys->def = wdev->wext.default_key;
if (wdev->wext.default_key != -1)
wdev->wext.connect.privacy = true;
}
if (!wdev->wext.connect.ssid_len)
return 0;
if (wdev->wext.keys && wdev->wext.keys->def != -1) {
ck = kmemdup(wdev->wext.keys, sizeof(*ck), GFP_KERNEL);
if (!ck)
return -ENOMEM;
for (i = 0; i < CFG80211_MAX_WEP_KEYS; i++)
ck->params[i].key = ck->data[i];
}
if (wdev->wext.prev_bssid_valid)
prev_bssid = wdev->wext.prev_bssid;
err = cfg80211_connect(rdev, wdev->netdev,
&wdev->wext.connect, ck, prev_bssid);
if (err)
kzfree(ck);
return err;
}
int cfg80211_mgd_wext_siwfreq(struct net_device *dev,
struct iw_request_info *info,
struct iw_freq *wextfreq, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
struct ieee80211_channel *chan = NULL;
int err, freq;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
freq = cfg80211_wext_freq(wextfreq);
if (freq < 0)
return freq;
if (freq) {
chan = ieee80211_get_channel(wdev->wiphy, freq);
if (!chan)
return -EINVAL;
if (chan->flags & IEEE80211_CHAN_DISABLED)
return -EINVAL;
}
wdev_lock(wdev);
if (wdev->conn) {
bool event = true;
if (wdev->wext.connect.channel == chan) {
err = 0;
goto out;
}
/* if SSID set, we'll try right again, avoid event */
if (wdev->wext.connect.ssid_len)
event = false;
err = cfg80211_disconnect(rdev, dev,
WLAN_REASON_DEAUTH_LEAVING, event);
if (err)
goto out;
}
wdev->wext.connect.channel = chan;
err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
return err;
}
int cfg80211_mgd_wext_giwfreq(struct net_device *dev,
struct iw_request_info *info,
struct iw_freq *freq, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct ieee80211_channel *chan = NULL;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
wdev_lock(wdev);
if (wdev->current_bss)
chan = wdev->current_bss->pub.channel;
else if (wdev->wext.connect.channel)
chan = wdev->wext.connect.channel;
wdev_unlock(wdev);
if (chan) {
freq->m = chan->center_freq;
freq->e = 6;
return 0;
}
/* no channel if not joining */
return -EINVAL;
}
int cfg80211_mgd_wext_siwessid(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *ssid)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
size_t len = data->length;
int err;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
if (!data->flags)
len = 0;
/* iwconfig uses nul termination in SSID.. */
if (len > 0 && ssid[len - 1] == '\0')
len--;
wdev_lock(wdev);
err = 0;
if (wdev->conn) {
bool event = true;
if (wdev->wext.connect.ssid && len &&
len == wdev->wext.connect.ssid_len &&
memcmp(wdev->wext.connect.ssid, ssid, len) == 0)
goto out;
/* if SSID set now, we'll try to connect, avoid event */
if (len)
event = false;
err = cfg80211_disconnect(rdev, dev,
WLAN_REASON_DEAUTH_LEAVING, event);
if (err)
goto out;
}
wdev->wext.prev_bssid_valid = false;
wdev->wext.connect.ssid = wdev->wext.ssid;
memcpy(wdev->wext.ssid, ssid, len);
wdev->wext.connect.ssid_len = len;
wdev->wext.connect.crypto.control_port = false;
wdev->wext.connect.crypto.control_port_ethertype =
cpu_to_be16(ETH_P_PAE);
err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
return err;
}
int cfg80211_mgd_wext_giwessid(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *ssid)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
int ret = 0;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
data->flags = 0;
wdev_lock(wdev);
if (wdev->current_bss) {
const u8 *ie;
rcu_read_lock();
ie = ieee80211_bss_get_ie(&wdev->current_bss->pub,
WLAN_EID_SSID);
if (ie) {
data->flags = 1;
data->length = ie[1];
if (data->length > IW_ESSID_MAX_SIZE)
ret = -EINVAL;
else
memcpy(ssid, ie + 2, data->length);
}
rcu_read_unlock();
} else if (wdev->wext.connect.ssid && wdev->wext.connect.ssid_len) {
data->flags = 1;
data->length = wdev->wext.connect.ssid_len;
memcpy(ssid, wdev->wext.connect.ssid, data->length);
}
wdev_unlock(wdev);
return ret;
}
int cfg80211_mgd_wext_siwap(struct net_device *dev,
struct iw_request_info *info,
struct sockaddr *ap_addr, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
u8 *bssid = ap_addr->sa_data;
int err;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
if (ap_addr->sa_family != ARPHRD_ETHER)
return -EINVAL;
/* automatic mode */
if (is_zero_ether_addr(bssid) || is_broadcast_ether_addr(bssid))
bssid = NULL;
wdev_lock(wdev);
if (wdev->conn) {
err = 0;
/* both automatic */
if (!bssid && !wdev->wext.connect.bssid)
goto out;
/* fixed already - and no change */
if (wdev->wext.connect.bssid && bssid &&
ether_addr_equal(bssid, wdev->wext.connect.bssid))
goto out;
err = cfg80211_disconnect(rdev, dev,
WLAN_REASON_DEAUTH_LEAVING, false);
if (err)
goto out;
}
if (bssid) {
memcpy(wdev->wext.bssid, bssid, ETH_ALEN);
wdev->wext.connect.bssid = wdev->wext.bssid;
} else
wdev->wext.connect.bssid = NULL;
err = cfg80211_mgd_wext_connect(rdev, wdev);
out:
wdev_unlock(wdev);
return err;
}
int cfg80211_mgd_wext_giwap(struct net_device *dev,
struct iw_request_info *info,
struct sockaddr *ap_addr, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
/* call only for station! */
if (WARN_ON(wdev->iftype != NL80211_IFTYPE_STATION))
return -EINVAL;
ap_addr->sa_family = ARPHRD_ETHER;
wdev_lock(wdev);
if (wdev->current_bss)
memcpy(ap_addr->sa_data, wdev->current_bss->pub.bssid, ETH_ALEN);
else
eth_zero_addr(ap_addr->sa_data);
wdev_unlock(wdev);
return 0;
}
int cfg80211_wext_siwgenie(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
u8 *ie = extra;
int ie_len = data->length, err;
if (wdev->iftype != NL80211_IFTYPE_STATION)
return -EOPNOTSUPP;
if (!ie_len)
ie = NULL;
wdev_lock(wdev);
/* no change */
err = 0;
if (wdev->wext.ie_len == ie_len &&
memcmp(wdev->wext.ie, ie, ie_len) == 0)
goto out;
if (ie_len) {
ie = kmemdup(extra, ie_len, GFP_KERNEL);
if (!ie) {
err = -ENOMEM;
goto out;
}
} else
ie = NULL;
kfree(wdev->wext.ie);
wdev->wext.ie = ie;
wdev->wext.ie_len = ie_len;
if (wdev->conn) {
err = cfg80211_disconnect(rdev, dev,
WLAN_REASON_DEAUTH_LEAVING, false);
if (err)
goto out;
}
/* userspace better not think we'll reconnect */
err = 0;
out:
wdev_unlock(wdev);
return err;
}
int cfg80211_wext_siwmlme(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *extra)
{
struct wireless_dev *wdev = dev->ieee80211_ptr;
struct iw_mlme *mlme = (struct iw_mlme *)extra;
struct cfg80211_registered_device *rdev;
int err;
if (!wdev)
return -EOPNOTSUPP;
rdev = wiphy_to_rdev(wdev->wiphy);
if (wdev->iftype != NL80211_IFTYPE_STATION)
return -EINVAL;
if (mlme->addr.sa_family != ARPHRD_ETHER)
return -EINVAL;
wdev_lock(wdev);
switch (mlme->cmd) {
case IW_MLME_DEAUTH:
case IW_MLME_DISASSOC:
err = cfg80211_disconnect(rdev, dev, mlme->reason_code, true);
break;
default:
err = -EOPNOTSUPP;
break;
}
wdev_unlock(wdev);
return err;
}