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=-20.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 B2B08C07E95 for ; Mon, 19 Jul 2021 15:44:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 935F961380 for ; Mon, 19 Jul 2021 15:44:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344865AbhGSPDX (ORCPT ); Mon, 19 Jul 2021 11:03:23 -0400 Received: from mail.kernel.org ([198.145.29.99]:59668 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345037AbhGSPBc (ORCPT ); Mon, 19 Jul 2021 11:01:32 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9501661001; Mon, 19 Jul 2021 15:42:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626709330; bh=e56wCNtzipbCruyvGQJOp9CBwWPfNJuoSaIZ7Nckhbc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kgeU7vq+QOJePTIYCneakTlSJ83o5KkVCvtyOVQEhoF09n2T4lzv6AN4xQGR99rGu FF7N0EfCFD1i3ghL9eUasAZYqspRMLqyjvz8Co0e1Wi2KiTCOi3je88twUYBM4cHOw 9CYyhAU+zHkBYNvSWNsgOY0hN7xt2TRK8OAQYiyQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Takashi Iwai , Sasha Levin Subject: [PATCH 4.19 341/421] ALSA: sb: Fix potential double-free of CSP mixer elements Date: Mon, 19 Jul 2021 16:52:32 +0200 Message-Id: <20210719144958.123991100@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144946.310399455@linuxfoundation.org> References: <20210719144946.310399455@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Takashi Iwai [ Upstream commit c305366a37441c2ac90b08711cb6f032b43672f2 ] snd_sb_qsound_destroy() contains the calls of removing the previously created mixer controls, but it doesn't clear the pointers. As snd_sb_qsound_destroy() itself may be repeatedly called via ioctl, this could lead to double-free potentially. Fix it by clearing the struct fields properly afterwards. Link: https://lore.kernel.org/r/20210608140540.17885-4-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- 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 2e00b64ef13b..b3eecde0b612 100644 --- a/sound/isa/sb/sb16_csp.c +++ b/sound/isa/sb/sb16_csp.c @@ -1086,10 +1086,14 @@ static void snd_sb_qsound_destroy(struct snd_sb_csp * p) card = p->chip->card; down_write(&card->controls_rwsem); - if (p->qsound_switch) + if (p->qsound_switch) { snd_ctl_remove(card, p->qsound_switch); - if (p->qsound_space) + p->qsound_switch = NULL; + } + if (p->qsound_space) { snd_ctl_remove(card, p->qsound_space); + p->qsound_space = NULL; + } up_write(&card->controls_rwsem); /* cancel pending transfer of QSound parameters */ -- 2.30.2