From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9D54C10F05 for ; Mon, 1 Apr 2019 17:39:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9969F20880 for ; Mon, 1 Apr 2019 17:39:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554140397; bh=cQIQRUeGy5YafTnevGzgHbp9ESkA6N3smCJmmL28qZQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=iXiasVjBS/mjH2SQEA3iI2Sd1mDrcwFax7EO0fGRfhmofLAaVbtrLxHD5K36ah8AK aoXr145l4aRz2DF/mWZQnMxuyK6+HZGEG6b1bJUTKYYpYVoj07N6fq2E3BdPaMqHYY nRXpJJgkinfmnKtgspkOsixy9HKThI+WspvT5DHM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388315AbfDARjk (ORCPT ); Mon, 1 Apr 2019 13:39:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:53496 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387934AbfDARjj (ORCPT ); Mon, 1 Apr 2019 13:39:39 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 151E4208E4; Mon, 1 Apr 2019 17:39:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1554140378; bh=cQIQRUeGy5YafTnevGzgHbp9ESkA6N3smCJmmL28qZQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aarQQxvuO057CtPNI7ciSSwZ1UVsIyx09gvW66ZpE/k3K2J2YYF1lTer6Ww4SSuyC bCKooFFEz/NKx7dMuNcHiOP90tTGNDU5t1d4IUx/UTZ5NA/tjLYXIWrAvzEKUa4KYc t4ipwMtfyQACPmhS4hnnLq1+kTXDx7uFy7eGoAgI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Marcel Holtmann , Johan Hedberg Subject: [PATCH 3.18 08/50] Bluetooth: Check L2CAP option sizes returned from l2cap_get_conf_opt Date: Mon, 1 Apr 2019 19:02:51 +0200 Message-Id: <20190401170041.970870927@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190401170041.257273804@linuxfoundation.org> References: <20190401170041.257273804@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marcel Holtmann commit af3d5d1c87664a4f150fcf3534c6567cb19909b0 upstream. When doing option parsing for standard type values of 1, 2 or 4 octets, the value is converted directly into a variable instead of a pointer. To avoid being tricked into being a pointer, check that for these option types that sizes actually match. In L2CAP every option is fixed size and thus it is prudent anyway to ensure that the remote side sends us the right option size along with option paramters. If the option size is not matching the option type, then that option is silently ignored. It is a protocol violation and instead of trying to give the remote attacker any further hints just pretend that option is not present and proceed with the default values. Implementation following the specification and its qualification procedures will always use the correct size and thus not being impacted here. To keep the code readable and consistent accross all options, a few cosmetic changes were also required. Signed-off-by: Marcel Holtmann Reviewed-by: Greg Kroah-Hartman Signed-off-by: Johan Hedberg Signed-off-by: Greg Kroah-Hartman --- net/bluetooth/l2cap_core.c | 77 ++++++++++++++++++++++++++------------------- 1 file changed, 46 insertions(+), 31 deletions(-) --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -3296,10 +3296,14 @@ static int l2cap_parse_conf_req(struct l switch (type) { case L2CAP_CONF_MTU: + if (olen != 2) + break; mtu = val; break; case L2CAP_CONF_FLUSH_TO: + if (olen != 2) + break; chan->flush_to = val; break; @@ -3307,26 +3311,30 @@ static int l2cap_parse_conf_req(struct l break; case L2CAP_CONF_RFC: - if (olen == sizeof(rfc)) - memcpy(&rfc, (void *) val, olen); + if (olen != sizeof(rfc)) + break; + memcpy(&rfc, (void *) val, olen); break; case L2CAP_CONF_FCS: + if (olen != 1) + break; if (val == L2CAP_FCS_NONE) set_bit(CONF_RECV_NO_FCS, &chan->conf_state); break; case L2CAP_CONF_EFS: - if (olen == sizeof(efs)) { - remote_efs = 1; - memcpy(&efs, (void *) val, olen); - } + if (olen != sizeof(efs)) + break; + remote_efs = 1; + memcpy(&efs, (void *) val, olen); break; case L2CAP_CONF_EWS: + if (olen != 2) + break; if (!chan->conn->hs_enabled) return -ECONNREFUSED; - set_bit(FLAG_EXT_CTRL, &chan->flags); set_bit(CONF_EWS_RECV, &chan->conf_state); chan->tx_win_max = L2CAP_DEFAULT_EXT_WINDOW; @@ -3336,7 +3344,6 @@ static int l2cap_parse_conf_req(struct l default: if (hint) break; - result = L2CAP_CONF_UNKNOWN; *((u8 *) ptr++) = type; break; @@ -3504,55 +3511,60 @@ static int l2cap_parse_conf_rsp(struct l switch (type) { case L2CAP_CONF_MTU: + if (olen != 2) + break; if (val < L2CAP_DEFAULT_MIN_MTU) { *result = L2CAP_CONF_UNACCEPT; chan->imtu = L2CAP_DEFAULT_MIN_MTU; } else chan->imtu = val; - l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu, endptr - ptr); + l2cap_add_conf_opt(&ptr, L2CAP_CONF_MTU, 2, chan->imtu, + endptr - ptr); break; case L2CAP_CONF_FLUSH_TO: + if (olen != 2) + break; chan->flush_to = val; - l2cap_add_conf_opt(&ptr, L2CAP_CONF_FLUSH_TO, - 2, chan->flush_to, endptr - ptr); + l2cap_add_conf_opt(&ptr, L2CAP_CONF_FLUSH_TO, 2, + chan->flush_to, endptr - ptr); break; case L2CAP_CONF_RFC: - if (olen == sizeof(rfc)) - memcpy(&rfc, (void *)val, olen); - + if (olen != sizeof(rfc)) + break; + memcpy(&rfc, (void *)val, olen); if (test_bit(CONF_STATE2_DEVICE, &chan->conf_state) && rfc.mode != chan->mode) return -ECONNREFUSED; - chan->fcs = 0; - - l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, - sizeof(rfc), (unsigned long) &rfc, endptr - ptr); + l2cap_add_conf_opt(&ptr, L2CAP_CONF_RFC, sizeof(rfc), + (unsigned long) &rfc, endptr - ptr); break; case L2CAP_CONF_EWS: + if (olen != 2) + break; chan->ack_win = min_t(u16, val, chan->ack_win); l2cap_add_conf_opt(&ptr, L2CAP_CONF_EWS, 2, chan->tx_win, endptr - ptr); break; case L2CAP_CONF_EFS: - if (olen == sizeof(efs)) { - memcpy(&efs, (void *)val, olen); - - if (chan->local_stype != L2CAP_SERV_NOTRAFIC && - efs.stype != L2CAP_SERV_NOTRAFIC && - efs.stype != chan->local_stype) - return -ECONNREFUSED; - - l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs), - (unsigned long) &efs, endptr - ptr); - } + if (olen != sizeof(efs)) + break; + memcpy(&efs, (void *)val, olen); + if (chan->local_stype != L2CAP_SERV_NOTRAFIC && + efs.stype != L2CAP_SERV_NOTRAFIC && + efs.stype != chan->local_stype) + return -ECONNREFUSED; + l2cap_add_conf_opt(&ptr, L2CAP_CONF_EFS, sizeof(efs), + (unsigned long) &efs, endptr - ptr); break; case L2CAP_CONF_FCS: + if (olen != 1) + break; if (*result == L2CAP_CONF_PENDING) if (val == L2CAP_FCS_NONE) set_bit(CONF_RECV_NO_FCS, @@ -3684,10 +3696,13 @@ static void l2cap_conf_rfc_get(struct l2 switch (type) { case L2CAP_CONF_RFC: - if (olen == sizeof(rfc)) - memcpy(&rfc, (void *)val, olen); + if (olen != sizeof(rfc)) + break; + memcpy(&rfc, (void *)val, olen); break; case L2CAP_CONF_EWS: + if (olen != 2) + break; txwin_ext = val; break; }