37 lines
1.3 KiB
Diff
37 lines
1.3 KiB
Diff
|
From ef566a4d4f74022e1fdb0a2addfe81e6de9f4aae Mon Sep 17 00:00:00 2001
|
||
|
|
From: Jouni Malinen <j@w1.fi>
|
||
|
|
Date: Wed, 29 Apr 2015 02:21:53 +0300
|
||
|
|
Subject: [PATCH] AP WMM: Fix integer underflow in WMM Action frame parser
|
||
|
|
|
||
|
|
The length of the WMM Action frame was not properly validated and the
|
||
|
|
length of the information elements (int left) could end up being
|
||
|
|
negative. This would result in reading significantly past the stack
|
||
|
|
buffer while parsing the IEs in ieee802_11_parse_elems() and while doing
|
||
|
|
so, resulting in segmentation fault.
|
||
|
|
|
||
|
|
This can result in an invalid frame being used for a denial of service
|
||
|
|
attack (hostapd process killed) against an AP with a driver that uses
|
||
|
|
hostapd for management frame processing (e.g., all mac80211-based
|
||
|
|
drivers).
|
||
|
|
|
||
|
|
Thanks to Kostya Kortchinsky of Google security team for discovering and
|
||
|
|
reporting this issue.
|
||
|
|
|
||
|
|
Signed-off-by: Jouni Malinen <j@w1.fi>
|
||
|
|
---
|
||
|
|
src/ap/wmm.c | 3 +++
|
||
|
|
1 file changed, 3 insertions(+)
|
||
|
|
|
||
|
|
--- a/src/ap/wmm.c
|
||
|
|
+++ b/src/ap/wmm.c
|
||
|
|
@@ -274,6 +274,9 @@ void hostapd_wmm_action(struct hostapd_d
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
+ if (left < 0)
|
||
|
|
+ return; /* not a valid WMM Action frame */
|
||
|
|
+
|
||
|
|
/* extract the tspec info element */
|
||
|
|
if (ieee802_11_parse_elems(pos, left, &elems, 1) == ParseFailed) {
|
||
|
|
hostapd_logger(hapd, mgmt->sa, HOSTAPD_MODULE_IEEE80211,
|