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[209.132.180.67]) by mx.google.com with ESMTP id b49si5447114eda.312.2019.10.27.14.29.51; Sun, 27 Oct 2019 14:30:14 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=UZi6TzBK; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732214AbfJ0VWn (ORCPT + 99 others); Sun, 27 Oct 2019 17:22:43 -0400 Received: from mail.kernel.org ([198.145.29.99]:43742 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732204AbfJ0VWl (ORCPT ); Sun, 27 Oct 2019 17:22:41 -0400 Received: from localhost (100.50.158.77.rev.sfr.net [77.158.50.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id EB4FA205C9; Sun, 27 Oct 2019 21:22:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1572211360; bh=V6ng7xpzLPI3DMpBaiK2pJdhQwz26GI1Xsq0xxxcOA8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=UZi6TzBKl9RbmP5lFhM6s9naaYbrMp018vMR40LfWGLShfZQ43GbXIaj+b+vVBHE6 8UQpJO6sGf/FDkYqDrop+u7/ZjTDJlTsyPvIsNLpBFszKFB1P9Y0uhVEWuUFEVmCQG 9NhAf6FpUUMGywto9NhzopRgeVJK4iyZQEEPNvB8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kees Cook , Nicolas Waisman , Will Deacon , Johannes Berg Subject: [PATCH 5.3 123/197] mac80211: Reject malformed SSID elements Date: Sun, 27 Oct 2019 22:00:41 +0100 Message-Id: <20191027203358.376623458@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191027203351.684916567@linuxfoundation.org> References: <20191027203351.684916567@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Will Deacon commit 4152561f5da3fca92af7179dd538ea89e248f9d0 upstream. Although this shouldn't occur in practice, it's a good idea to bounds check the length field of the SSID element prior to using it for things like allocations or memcpy operations. Cc: Cc: Kees Cook Reported-by: Nicolas Waisman Signed-off-by: Will Deacon Link: https://lore.kernel.org/r/20191004095132.15777-1-will@kernel.org Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman --- net/mac80211/mlme.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/net/mac80211/mlme.c +++ b/net/mac80211/mlme.c @@ -2629,7 +2629,8 @@ struct sk_buff *ieee80211_ap_probereq_ge rcu_read_lock(); ssid = ieee80211_bss_get_ie(cbss, WLAN_EID_SSID); - if (WARN_ON_ONCE(ssid == NULL)) + if (WARN_ONCE(!ssid || ssid[1] > IEEE80211_MAX_SSID_LEN, + "invalid SSID element (len=%d)", ssid ? ssid[1] : -1)) ssid_len = 0; else ssid_len = ssid[1]; @@ -5227,7 +5228,7 @@ int ieee80211_mgd_assoc(struct ieee80211 rcu_read_lock(); ssidie = ieee80211_bss_get_ie(req->bss, WLAN_EID_SSID); - if (!ssidie) { + if (!ssidie || ssidie[1] > sizeof(assoc_data->ssid)) { rcu_read_unlock(); kfree(assoc_data); return -EINVAL;