From patchwork Tue Apr 26 08:20:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 566619 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 C7045C4332F for ; Tue, 26 Apr 2022 08:44:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345767AbiDZIrc (ORCPT ); Tue, 26 Apr 2022 04:47:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57816 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346899AbiDZIp3 (ORCPT ); Tue, 26 Apr 2022 04:45:29 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8F93611C3D; Tue, 26 Apr 2022 01:36:27 -0700 (PDT) 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 2C85E617E7; Tue, 26 Apr 2022 08:36:27 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 27257C385AC; Tue, 26 Apr 2022 08:36:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1650962186; bh=NVsQUUF/tJdoP9yIQoTGPFAQXLh4WYEGBYuFJEQX1SE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=OrL9imO4aqcB3y8aNIZSDL4nxv4eP61jJusEIl6osKeQ1uuLBDK3tBt8LVYviTCK+ 0ePvMCmRJDinbAXnsiDHusjc5EN51tVREqjR5FHq7Yxgf0XXy7UQExsOb8EDAKd903 MqvmpzSztLWCRdYbXD8Dpy2A91D2MYEmr5dhwjz8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+70e777a39907d6d5fd0a@syzkaller.appspotmail.com, Takashi Iwai Subject: [PATCH 5.15 015/124] ALSA: usb-audio: Clear MIDI port active flag after draining Date: Tue, 26 Apr 2022 10:20:16 +0200 Message-Id: <20220426081747.734351104@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220426081747.286685339@linuxfoundation.org> References: <20220426081747.286685339@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Takashi Iwai commit 0665886ad1392e6b5bae85d7a6ccbed48dca1522 upstream. When a rawmidi output stream is closed, it calls the drain at first, then does trigger-off only when the drain returns -ERESTARTSYS as a fallback. It implies that each driver should turn off the stream properly after the drain. Meanwhile, USB-audio MIDI interface didn't change the port->active flag after the drain. This may leave the output work picking up the port that is closed right now, which eventually leads to a use-after-free for the already released rawmidi object. This patch fixes the bug by properly clearing the port->active flag after the output drain. Reported-by: syzbot+70e777a39907d6d5fd0a@syzkaller.appspotmail.com Cc: Link: https://lore.kernel.org/r/00000000000011555605dceaff03@google.com Link: https://lore.kernel.org/r/20220420130247.22062-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/midi.c | 1 + 1 file changed, 1 insertion(+) --- a/sound/usb/midi.c +++ b/sound/usb/midi.c @@ -1194,6 +1194,7 @@ static void snd_usbmidi_output_drain(str } while (drain_urbs && timeout); finish_wait(&ep->drain_wait, &wait); } + port->active = 0; spin_unlock_irq(&ep->buffer_lock); }