From patchwork Tue Apr 28 18:24:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 226919 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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 B4F06C83007 for ; Tue, 28 Apr 2020 18:32:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 95AEE21927 for ; Tue, 28 Apr 2020 18:32:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588098758; bh=UcH5qtw59qTuXTBw6ECJdi8TpzL+afl6G6oGjx9V0XA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=oVatQnof4xQPkciNKGC0Cv56oIFGOksunoIw6oWPYHUYw5g67iRSInQdnhbpHlSNa axwwbnL3pMJQmeJ2Cn2/Jy4opz4srHMGos9qVQAdhpAsT5nc/mYrgVKS4nds5l3HyN 6CNxgfl2SZJPLA3jZxKgbOleCrl6JRoewqezxK04= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729831AbgD1Sch (ORCPT ); Tue, 28 Apr 2020 14:32:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:48816 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729827AbgD1Scg (ORCPT ); Tue, 28 Apr 2020 14:32:36 -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 6AD4720B80; Tue, 28 Apr 2020 18:32:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1588098755; bh=UcH5qtw59qTuXTBw6ECJdi8TpzL+afl6G6oGjx9V0XA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xYblkT0Rra2pjdwFZBpiU6pV3PPwRw7mnCq2L4JF2vpatFcXEUXsjKw+rcnyDFrhj EyqH/GQ4uyDJ+LMh54nTMaFnTi7WNnCFy4o7afp9+YEbZ8qwU+kkwMk5yaFhDOltK7 eHmNLI0K2X4BOkI5L097rhpfP/PNqtG6zgy/2Nns= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiyu Yang , Xin Tan , Takashi Iwai Subject: [PATCH 5.6 107/167] ALSA: usb-audio: Fix usb audio refcnt leak when getting spdif Date: Tue, 28 Apr 2020 20:24:43 +0200 Message-Id: <20200428182238.696554233@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200428182225.451225420@linuxfoundation.org> References: <20200428182225.451225420@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xiyu Yang commit 59e1947ca09ebd1cae147c08c7c41f3141233c84 upstream. snd_microii_spdif_default_get() invokes snd_usb_lock_shutdown(), which increases the refcount of the snd_usb_audio object "chip". When snd_microii_spdif_default_get() returns, local variable "chip" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in several exception handling paths of snd_microii_spdif_default_get(). When those error scenarios occur such as usb_ifnum_to_if() returns NULL, the function forgets to decrease the refcnt increased by snd_usb_lock_shutdown(), causing a refcnt leak. Fix this issue by jumping to "end" label when those error scenarios occur. Fixes: 447d6275f0c2 ("ALSA: usb-audio: Add sanity checks for endpoint accesses") Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Cc: Link: https://lore.kernel.org/r/1587617711-13200-1-git-send-email-xiyuyang19@fudan.edu.cn Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/mixer_quirks.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) --- a/sound/usb/mixer_quirks.c +++ b/sound/usb/mixer_quirks.c @@ -1508,11 +1508,15 @@ static int snd_microii_spdif_default_get /* use known values for that card: interface#1 altsetting#1 */ iface = usb_ifnum_to_if(chip->dev, 1); - if (!iface || iface->num_altsetting < 2) - return -EINVAL; + if (!iface || iface->num_altsetting < 2) { + err = -EINVAL; + goto end; + } alts = &iface->altsetting[1]; - if (get_iface_desc(alts)->bNumEndpoints < 1) - return -EINVAL; + if (get_iface_desc(alts)->bNumEndpoints < 1) { + err = -EINVAL; + goto end; + } ep = get_endpoint(alts, 0)->bEndpointAddress; err = snd_usb_ctl_msg(chip->dev,