[PATCH 3.16 276/370] mac80211: Fix adding of mesh vendor IEs

Ben Hutchings
2017-03-10T13:44:08Z

From: Thorsten Horstmann <thorsten@defutech.de>

commit da7061c82e4a1bc6a5e134ef362c86261906c860 upstream.

The function ieee80211_ie_split_vendor doesn't return 0 on errors. Instead
it returns any offset < ielen when WLAN_EID_VENDOR_SPECIFIC is found. The
return value in mesh_add_vendor_ies must therefore be checked against
ifmsh->ie_len and not 0. Otherwise all ifmsh->ie starting with
WLAN_EID_VENDOR_SPECIFIC will be rejected.

Fixes: 082ebb0c258d ("mac80211: fix mesh beacon format")
Signed-off-by: Thorsten Horstmann <thorsten@defutech.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fit.fraunhofer.de>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
[sven@narfation.org: Add commit message]
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
net/mac80211/mesh.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -352,7 +352,7 @@ int mesh_add_vendor_ies(struct ieee80211
/* fast-forward to vendor IEs */
offset = ieee80211_ie_split_vendor(ifmsh->ie, ifmsh->ie_len, 0);

- if (offset) {
+ if (offset < ifmsh->ie_len) {
len = ifmsh->ie_len - offset;
data = ifmsh->ie + offset;
if (skb_tailroom(skb) < len)