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=-10.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 64414C43331 for ; Thu, 26 Mar 2020 23:31:10 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id E169520663 for ; Thu, 26 Mar 2020 23:31:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="tbE3nuax"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="mewPN6wZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E169520663 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 2CBB2167A; Fri, 27 Mar 2020 00:30:18 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 2CBB2167A DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1585265468; bh=1icnrn7p37qkHPzDlfJGDOpKxQZ/CgwxVjnbbBMR+l0=; h=From:To:Subject:Date:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=tbE3nuaxpbmn1xl7oBcX+IS6sbNyf2/zURa2WafEwQePU31W+PSG6WG/UbUgv0YC3 TuwwKVzBdcFuX+pqNJhKDQnDwpmAyVgnNEJu/aEljJccidcIv0Hmp/wrPWcjwbiJds pNgd54kiM7EawRGUoBb2dsvAFjp02ceKizYTKwCM= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 132E7F802FB; Fri, 27 Mar 2020 00:25:21 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 9102AF802F8; Fri, 27 Mar 2020 00:25:17 +0100 (CET) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id BC433F80249 for ; Fri, 27 Mar 2020 00:25:11 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz BC433F80249 Authentication-Results: alsa1.perex.cz; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="mewPN6wZ" Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id BD2E420774; Thu, 26 Mar 2020 23:25:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1585265110; bh=1icnrn7p37qkHPzDlfJGDOpKxQZ/CgwxVjnbbBMR+l0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mewPN6wZ6AftMVqe68ubfBw9P5QjbjOMBiMpMSc7XKlM1KIEYfRVSG9zdsdMXqb/q +CR27yEmlMK9/28zKOLwgRQ4orThczosijE80PI41slLkGDN2s9pkREp+rMY6WR06S 8MuWqVOTgd0qW0cBARW77M05mZdMNJ1dRrrA/eq4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 13/15] ALSA: line6: Fix endless MIDI read loop Date: Thu, 26 Mar 2020 19:24:53 -0400 Message-Id: <20200326232455.8029-13-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200326232455.8029-1-sashal@kernel.org> References: <20200326232455.8029-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Cc: Takashi Iwai , Sasha Levin , alsa-devel@alsa-project.org, syzbot+cce32521ee0a824c21f7@syzkaller.appspotmail.com X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" From: Takashi Iwai [ Upstream commit d683469b3c93d7e2afd39e6e1970f24700eb7a68 ] The MIDI input event parser of the LINE6 driver may enter into an endless loop when the unexpected data sequence is given, as it tries to continue the secondary bytes without termination. Also, when the input data is too short, the parser returns a negative error, while the caller doesn't handle it properly. This would lead to the unexpected behavior as well. This patch addresses those issues by checking the return value correctly and handling the one-byte event in the parser properly. The bug was reported by syzkaller. Reported-by: syzbot+cce32521ee0a824c21f7@syzkaller.appspotmail.com Cc: Link: https://lore.kernel.org/r/000000000000033087059f8f8fa3@google.com Link: https://lore.kernel.org/r/20200309095922.30269-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/usb/line6/driver.c | 2 +- sound/usb/line6/midibuf.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/sound/usb/line6/driver.c b/sound/usb/line6/driver.c index bbcb0d4d83aec..0193d4989107b 100644 --- a/sound/usb/line6/driver.c +++ b/sound/usb/line6/driver.c @@ -320,7 +320,7 @@ static void line6_data_received(struct urb *urb) line6_midibuf_read(mb, line6->buffer_message, LINE6_MIDI_MESSAGE_MAXLEN); - if (done == 0) + if (done <= 0) break; line6->message_length = done; diff --git a/sound/usb/line6/midibuf.c b/sound/usb/line6/midibuf.c index 36a610ba342ec..c931d48801ebe 100644 --- a/sound/usb/line6/midibuf.c +++ b/sound/usb/line6/midibuf.c @@ -163,7 +163,7 @@ int line6_midibuf_read(struct midi_buffer *this, unsigned char *data, int midi_length_prev = midibuf_message_length(this->command_prev); - if (midi_length_prev > 0) { + if (midi_length_prev > 1) { midi_length = midi_length_prev - 1; repeat = 1; } else -- 2.20.1