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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 857BEC4332F for ; Mon, 12 Dec 2022 10:45:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231626AbiLLKpA (ORCPT ); Mon, 12 Dec 2022 05:45:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33738 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232140AbiLLKl0 (ORCPT ); Mon, 12 Dec 2022 05:41:26 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08E4C101EC; Mon, 12 Dec 2022 02:36:54 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 68DB660F91; Mon, 12 Dec 2022 10:36:54 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E70CC433D2; Mon, 12 Dec 2022 10:36:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1670841413; bh=eiCfIRMdbE8pkOzxRpMs6zkbpeaB+spZT5DgtWEvpyY=; h=From:To:Cc:Subject:Date:From; b=GvmaBw91WYnF530kMGVijDqz54gR5UMkC5ZBlG8BiUXwc/JL4ry7uuvbto27Vt0BT sMX+IyrCaRiuGDPEZcuaxjysWsBWKKceIL6f+A5GCS4OeSd1sy4qKfnrj8wRq1E0Dv imDwXXzEU9K7deARpdvZ8D32SFZKLQeOlVrh2RiVl+7FzPxZVLABeFxD7EC1f1j7nI D2Io9kk9u+VNp4a+L/c6QIRq6q/khbDtZoDDnFQLzOWHbSy3PD4oJfCF104T7HeiJ7 242XuU0eB7yVUp3FTcxzjMbhM9Obm22eTc85kgpRvndpwvC8SsBkWA/rMzE2afD9cP sJfQpbRQl/fhQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sungwoo Kim , Luiz Augusto von Dentz , Sasha Levin , marcel@holtmann.org, johan.hedberg@gmail.com, luiz.dentz@gmail.com, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, linux-bluetooth@vger.kernel.org, netdev@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 1/2] Bluetooth: L2CAP: Fix u8 overflow Date: Mon, 12 Dec 2022 05:36:48 -0500 Message-Id: <20221212103650.300515-1-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sungwoo Kim [ Upstream commit bcd70260ef56e0aee8a4fc6cd214a419900b0765 ] By keep sending L2CAP_CONF_REQ packets, chan->num_conf_rsp increases multiple times and eventually it will wrap around the maximum number (i.e., 255). This patch prevents this by adding a boundary check with L2CAP_MAX_CONF_RSP Btmon log: Bluetooth monitor ver 5.64 = Note: Linux version 6.1.0-rc2 (x86_64) 0.264594 = Note: Bluetooth subsystem version 2.22 0.264636 @ MGMT Open: btmon (privileged) version 1.22 {0x0001} 0.272191 = New Index: 00:00:00:00:00:00 (Primary,Virtual,hci0) [hci0] 13.877604 @ RAW Open: 9496 (privileged) version 2.22 {0x0002} 13.890741 = Open Index: 00:00:00:00:00:00 [hci0] 13.900426 (...) > ACL Data RX: Handle 200 flags 0x00 dlen 1033 #32 [hci0] 14.273106 invalid packet size (12 != 1033) 08 00 01 00 02 01 04 00 01 10 ff ff ............ > ACL Data RX: Handle 200 flags 0x00 dlen 1547 #33 [hci0] 14.273561 invalid packet size (14 != 1547) 0a 00 01 00 04 01 06 00 40 00 00 00 00 00 ........@..... > ACL Data RX: Handle 200 flags 0x00 dlen 2061 #34 [hci0] 14.274390 invalid packet size (16 != 2061) 0c 00 01 00 04 01 08 00 40 00 00 00 00 00 00 04 ........@....... > ACL Data RX: Handle 200 flags 0x00 dlen 2061 #35 [hci0] 14.274932 invalid packet size (16 != 2061) 0c 00 01 00 04 01 08 00 40 00 00 00 07 00 03 00 ........@....... = bluetoothd: Bluetooth daemon 5.43 14.401828 > ACL Data RX: Handle 200 flags 0x00 dlen 1033 #36 [hci0] 14.275753 invalid packet size (12 != 1033) 08 00 01 00 04 01 04 00 40 00 00 00 ........@... Signed-off-by: Sungwoo Kim Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin --- net/bluetooth/l2cap_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index fd6cd47a6c5a..fd95631205a6 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -4193,7 +4193,8 @@ static inline int l2cap_config_req(struct l2cap_conn *conn, chan->ident = cmd->ident; l2cap_send_cmd(conn, cmd->ident, L2CAP_CONF_RSP, len, rsp); - chan->num_conf_rsp++; + if (chan->num_conf_rsp < L2CAP_CONF_MAX_CONF_RSP) + chan->num_conf_rsp++; /* Reset config buffer. */ chan->conf_len = 0; -- 2.35.1