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=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 845C2C433B4 for ; Mon, 26 Apr 2021 14:56:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3792261166 for ; Mon, 26 Apr 2021 14:56:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233928AbhDZO4n (ORCPT ); Mon, 26 Apr 2021 10:56:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52734 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233573AbhDZO4m (ORCPT ); Mon, 26 Apr 2021 10:56:42 -0400 Received: from ustc.edu.cn (email6.ustc.edu.cn [IPv6:2001:da8:d800::8]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id E03DBC061574 for ; Mon, 26 Apr 2021 07:55:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mail.ustc.edu.cn; s=dkim; h=Received:From:To:Cc:Subject:Date: Message-Id:MIME-Version:Content-Transfer-Encoding; bh=A2FocN77VX MDjpadCXSomBmGUVlCTli6sa6q6oxFZho=; b=F4mm6NBCtoER2dRHbI4/I3z9F4 atvrEruktMAdW1BQTigk4SlLAqRTWGxFToB1MwIz76c8QWRz5f4hGloGkXC4akaj 2CzvmP0Q1O05RUKEX32Q8K349tYGmbgmoKp8xK5CfmRtg6s0t327RUY0SxtDZLzy 2eIltAef9rWat/i10= Received: from ubuntu.localdomain (unknown [202.38.69.14]) by newmailweb.ustc.edu.cn (Coremail) with SMTP id LkAmygD3_59v1IZgS4pLAA--.6373S4; Mon, 26 Apr 2021 22:55:43 +0800 (CST) From: Lv Yunlong To: perex@perex.cz, tiwai@suse.com Cc: alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org, Lv Yunlong Subject: [PATCH] sound/isa/ib: Fix two use after free in snd_sb_qsound_build Date: Mon, 26 Apr 2021 07:55:41 -0700 Message-Id: <20210426145541.8070-1-lyl2019@mail.ustc.edu.cn> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CM-TRANSID: LkAmygD3_59v1IZgS4pLAA--.6373S4 X-Coremail-Antispam: 1UD129KBjvJXoW7CF15tryfJFyDAw1fAw1xAFb_yoW8Wr43pF 95Zas7C348Ar1vka4aqr1UW340krWvyFy5Zw4UWa4fAr15Jrn3G348tw13Aw47uF1Sk3yU W347A3s5JasIyaDanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUvC14x267AKxVW8JVW5JwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26F1j6w1UM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26r4U JVWxJr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_Gc CE3s1lnxkEFVAIw20F6cxK64vIFxWle2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xv F2IEw4CE5I8CrVC2j2WlYx0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r 4UMcvjeVCFs4IE7xkEbVWUJVW8JwACjcxG0xvY0x0EwIxGrwACjI8F5VA0II8E6IAqYI8I 648v4I1lc2xSY4AK67AK6ry5MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY6r1j6r 4UMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7xvwVAFwI0_JrI_JrWlx4CE17CEb7AF 67AKxVWUAVWUtwCIc40Y0x0EwIxGrwCI42IY6xIIjxv20xvE14v26r1j6r1xMIIF0xvE2I x0cI8IcVCY1x0267AKxVWUJVW8JwCI42IY6xAIw20EY4v20xvaj40_Wr1j6rW3Jr1lIxAI cVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVW8JVW8JrUvcSsGvfC2Kf nxnUUI43ZEXa7VUbSdgPUUUUU== X-CM-SenderInfo: ho1ojiyrz6zt1loo32lwfovvfxof0/ Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In snd_sb_qsound_build, snd_ctl_add(..,p->qsound_switch...) and snd_ctl_add(..,p->qsound_space..) are called. But the second arguments of snd_ctl_add() could be freed via snd_ctl_add_replace() ->snd_ctl_free_one(). After the error code is returned, snd_sb_qsound_destroy(p) is called in __error branch. But in snd_sb_qsound_destroy(), the freed p->qsound_switch and p->qsound_space are still used by snd_ctl_remove(). My patch set p->qsound_switch and p->qsound_space to NULL if snd_ctl_add() failed to avoid the uaf bugs. But these codes need to further be improved with the code style. Signed-off-by: Lv Yunlong --- sound/isa/sb/sb16_csp.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/sound/isa/sb/sb16_csp.c b/sound/isa/sb/sb16_csp.c index 8635a2b6b36b..4789345a8fdd 100644 --- a/sound/isa/sb/sb16_csp.c +++ b/sound/isa/sb/sb16_csp.c @@ -1045,10 +1045,14 @@ static int snd_sb_qsound_build(struct snd_sb_csp * p) spin_lock_init(&p->q_lock); - if ((err = snd_ctl_add(card, p->qsound_switch = snd_ctl_new1(&snd_sb_qsound_switch, p))) < 0) + if ((err = snd_ctl_add(card, p->qsound_switch = snd_ctl_new1(&snd_sb_qsound_switch, p))) < 0) { + p->qsound_switch = NULL; goto __error; - if ((err = snd_ctl_add(card, p->qsound_space = snd_ctl_new1(&snd_sb_qsound_space, p))) < 0) + } + if ((err = snd_ctl_add(card, p->qsound_space = snd_ctl_new1(&snd_sb_qsound_space, p))) < 0) { + p->qsound_space = NULL; goto __error; + } return 0; -- 2.25.1