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authorWill Deacon <will@kernel.org>2019-10-04 12:51:32 +0300
committerJohannes Berg <johannes.berg@intel.com>2019-10-04 15:04:08 +0300
commit4ac2813cc867ae563a1ba5a9414bfb554e5796fa (patch)
treece2debc1c58aec090511a3df0ac5ad9b5ef33a37 /net/wireless
parent4152561f5da3fca92af7179dd538ea89e248f9d0 (diff)
downloadlinux-4ac2813cc867ae563a1ba5a9414bfb554e5796fa.tar.xz
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>
Diffstat (limited to 'net/wireless')
-rw-r--r--net/wireless/wext-sme.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/net/wireless/wext-sme.c b/net/wireless/wext-sme.c
index c67d7a82ab13..73fd0eae08ca 100644
--- a/net/wireless/wext-sme.c
+++ b/net/wireless/wext-sme.c
@@ -202,6 +202,7 @@ int cfg80211_mgd_wext_giwessid(struct net_device *dev,
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))
@@ -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,