diff options
| author | Will Deacon <will@kernel.org> | 2019-10-04 10:51:32 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2019-11-15 00:56:56 +0000 |
| commit | e70efb76ea2eb9f08dc627d93d35a8e5c065346d (patch) | |
| tree | 51241f72da7e26db1add782c5e9534f5a1d56343 | |
| parent | bc3d2e9cfdc5c1b7e5ed34eb5279e47d462b4d5c (diff) | |
cfg80211: wext: avoid copying malformed SSIDs
commit 4ac2813cc867ae563a1ba5a9414bfb554e5796fa upstream.
Ensure the SSID element is bounds-checked prior to invoking memcpy()
with its length field, when copying to userspace.
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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | net/wireless/wext-sme.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/net/wireless/wext-sme.c b/net/wireless/wext-sme.c index c7e5c8eb4f24..e95b5e949406 100644 --- a/net/wireless/wext-sme.c +++ b/net/wireless/wext-sme.c @@ -225,6 +225,7 @@ 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)) @@ -242,7 +243,10 @@ 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) { @@ -252,7 +256,7 @@ 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, |