From patchwork Thu Apr 14 13:09:06 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: 561908 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 CA71BC43217 for ; Thu, 14 Apr 2022 13:18:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243815AbiDNNU3 (ORCPT ); Thu, 14 Apr 2022 09:20:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38450 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243876AbiDNNTD (ORCPT ); Thu, 14 Apr 2022 09:19:03 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D9D269286D; Thu, 14 Apr 2022 06:16:22 -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 ams.source.kernel.org (Postfix) with ESMTPS id 7F2B4B8296A; Thu, 14 Apr 2022 13:16:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E8ABFC385A5; Thu, 14 Apr 2022 13:16:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649942180; bh=6118wY5SUqvaOGFyKq6KoocM37LhFJT1VLYB+36B0Ig=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ST0AlKaw9J+46r+N4C/ETmEAK059dx1ke9usI72V5dzhzA3fuC9OZNo13/3rAhuzk x9mjX5d1ucxAs0tmeC8A5deojT/jjA8n55DID1S5WyMTndTnF124OCbuB22G0pxRsd 6UMaS6WKgeEIAArFVLKnYdyQD7aASyug4iASm/ng= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xiaomeng Tong , Takashi Iwai Subject: [PATCH 4.19 043/338] ALSA: cs4236: fix an incorrect NULL check on list iterator Date: Thu, 14 Apr 2022 15:09:06 +0200 Message-Id: <20220414110840.122748349@linuxfoundation.org> X-Mailer: git-send-email 2.35.2 In-Reply-To: <20220414110838.883074566@linuxfoundation.org> References: <20220414110838.883074566@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Xiaomeng Tong commit 0112f822f8a6d8039c94e0bc9b264d7ffc5d4704 upstream. The bug is here: err = snd_card_cs423x_pnp(dev, card->private_data, pdev, cdev); The list iterator value 'cdev' will *always* be set and non-NULL by list_for_each_entry(), so it is incorrect to assume that the iterator value will be NULL if the list is empty or no element is found. To fix the bug, use a new variable 'iter' as the list iterator, while use the original variable 'cdev' as a dedicated pointer to point to the found element. And snd_card_cs423x_pnp() itself has NULL check for cdev. Cc: stable@vger.kernel.org Fixes: c2b73d1458014 ("ALSA: cs4236: cs4232 and cs4236 driver merge to solve PnP BIOS detection") Signed-off-by: Xiaomeng Tong Link: https://lore.kernel.org/r/20220327060822.4735-1-xiam0nd.tong@gmail.com Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/isa/cs423x/cs4236.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) --- a/sound/isa/cs423x/cs4236.c +++ b/sound/isa/cs423x/cs4236.c @@ -559,7 +559,7 @@ static int snd_cs423x_pnpbios_detect(str static int dev; int err; struct snd_card *card; - struct pnp_dev *cdev; + struct pnp_dev *cdev, *iter; char cid[PNP_ID_LEN]; if (pnp_device_is_isapnp(pdev)) @@ -575,9 +575,11 @@ static int snd_cs423x_pnpbios_detect(str strcpy(cid, pdev->id[0].id); cid[5] = '1'; cdev = NULL; - list_for_each_entry(cdev, &(pdev->protocol->devices), protocol_list) { - if (!strcmp(cdev->id[0].id, cid)) + list_for_each_entry(iter, &(pdev->protocol->devices), protocol_list) { + if (!strcmp(iter->id[0].id, cid)) { + cdev = iter; break; + } } err = snd_cs423x_card_new(&pdev->dev, dev, &card); if (err < 0)