Ensure the SSID element is bounds-checked prior to invoking memcpy()
with its length field.
Cc: <stable@xxxxxxxxxxxxxxx>
Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Reported-by: Nicolas Waisman <nico@xxxxxxxxxx>
Signed-off-by: Will Deacon <will@xxxxxxxxxx>
---
net/wireless/wext-sme.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/wireless/wext-sme.c b/net/wireless/wext-sme.c
index c67d7a82ab13..3fd2cc7fc36a 100644
--- a/net/wireless/wext-sme.c
+++ b/net/wireless/wext-sme.c
@@ -201,6 +201,7 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev,
struct iw_request_info *info,
struct iw_point *data, char *ssid)
{
+ int ret = 0;
struct wireless_dev *wdev = dev->ieee80211_ptr;
/* call only for station! */
@@ -219,7 +220,10 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev,
if (ie) {
data->flags = 1;
data->length = ie[1];
- memcpy(ssid, ie + 2, data->length);
+ 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) {
@@ -229,7 +233,7 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev,
}
wdev_unlock(wdev);
- return 0;
+ return ret;
}
int cfg80211_mgd_wext_siwap(struct net_device *dev,
--
2.23.0.581.g78d2f28ef7-goog
