Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938738AbcJ2O1q (ORCPT ); Sat, 29 Oct 2016 10:27:46 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:48962 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934855AbcJ2NuG (ORCPT ); Sat, 29 Oct 2016 09:50:06 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daxing Guo , Hante Meuleman , Pieter-Paul Giesberts , Franky Lin , Arend van Spriel , Kalle Valo , Juerg Haefliger Subject: [PATCH 4.4 18/51] brcmfmac: avoid potential stack overflow in brcmf_cfg80211_start_ap() Date: Sat, 29 Oct 2016 09:49:19 -0400 Message-Id: <20161029134923.248241791@linuxfoundation.org> X-Mailer: git-send-email 2.10.1 In-Reply-To: <20161029134922.501052551@linuxfoundation.org> References: <20161029134922.501052551@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1535 Lines: 39 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Arend Van Spriel commit ded89912156b1a47d940a0c954c43afbabd0c42c upstream. User-space can choose to omit NL80211_ATTR_SSID and only provide raw IE TLV data. When doing so it can provide SSID IE with length exceeding the allowed size. The driver further processes this IE copying it into a local variable without checking the length. Hence stack can be corrupted and used as exploit. Reported-by: Daxing Guo Reviewed-by: Hante Meuleman Reviewed-by: Pieter-Paul Giesberts Reviewed-by: Franky Lin Signed-off-by: Arend van Spriel Signed-off-by: Kalle Valo Signed-off-by: Juerg Haefliger Signed-off-by: Greg Kroah-Hartman --- drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c +++ b/drivers/net/wireless/brcm80211/brcmfmac/cfg80211.c @@ -4102,7 +4102,7 @@ brcmf_cfg80211_start_ap(struct wiphy *wi (u8 *)&settings->beacon.head[ie_offset], settings->beacon.head_len - ie_offset, WLAN_EID_SSID); - if (!ssid_ie) + if (!ssid_ie || ssid_ie->len > IEEE80211_MAX_SSID_LEN) return -EINVAL; memcpy(ssid_le.SSID, ssid_ie->data, ssid_ie->len);