From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from vs166246.vserver.de ([62.75.166.246]:58133 "EHLO vs166246.vserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752083AbXL0VQo (ORCPT ); Thu, 27 Dec 2007 16:16:44 -0500 From: Michael Buesch To: John Linville Subject: [PATCH] b43: Fix tim search buffer overrun Date: Thu, 27 Dec 2007 22:15:11 +0100 Cc: bcm43xx-dev@lists.berlios.de, linux-wireless@vger.kernel.org, Johannes Berg , Stefano Brivio MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Message-Id: <200712272215.12056.mb@bu3sch.de> (sfid-20071227_211650_685107_0251322E) Sender: linux-wireless-owner@vger.kernel.org List-ID: Use the length of the variable section of the beacon instead of the whole beacon length for bounds checking. Signed-off-by: Michael Buesch Index: wireless-2.6/drivers/net/wireless/b43/main.c =================================================================== --- wireless-2.6.orig/drivers/net/wireless/b43/main.c 2007-12-26 18:20:38.000000000 +0100 +++ wireless-2.6/drivers/net/wireless/b43/main.c 2007-12-27 22:05:07.000000000 +0100 @@ -1161,7 +1161,7 @@ static void b43_write_beacon_template(st u16 ram_offset, u16 shm_size_offset, u8 rate) { - int i, len; + unsigned int i, len, variable_len; const struct ieee80211_mgmt *bcn; const u8 *ie; bool tim_found = 0; @@ -1176,7 +1176,8 @@ static void b43_write_beacon_template(st /* Find the position of the TIM and the DTIM_period value * and write them to SHM. */ ie = bcn->u.beacon.variable; - for (i = 0; i < len - 2; ) { + variable_len = len - offsetof(struct ieee80211_mgmt, u.beacon.variable); + for (i = 0; i < variable_len - 2; ) { uint8_t ie_id, ie_len; ie_id = ie[i]; @@ -1187,7 +1188,7 @@ static void b43_write_beacon_template(st /* This is the TIM Information Element */ /* Check whether the ie_len is in the beacon data range. */ - if (len < ie_len + 2 + i) + if (variable_len < ie_len + 2 + i) break; /* A valid TIM is at least 4 bytes long. */ if (ie_len < 4)