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=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 57E5CC07E99 for ; Sat, 10 Jul 2021 02:43:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 43DDF613BE for ; Sat, 10 Jul 2021 02:43:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235478AbhGJCpq (ORCPT ); Fri, 9 Jul 2021 22:45:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:33772 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235365AbhGJCnq (ORCPT ); Fri, 9 Jul 2021 22:43:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B4532613F5; Sat, 10 Jul 2021 02:39:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1625884765; bh=0maWroivBJOvh18abpe9bTk7gxcjye2N3W9KBM9/MHA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bvPQhzPofrmCADB5Y2K2PVmQyIvk8uhUaQSuQBy0irTpkCBH2eibm9Lcdit3F3pZA 0fbCiti5q7wIWHXqlQG/axnk2APAr3dgwkMHfu7MgqmZYPUekEaFV0maveu5wKhK/p JakBOiFBhQtKqFr5DVMKY/CZyCuYNt7cZGjPl9Hfdb2S5q/DdDyJoOoWT9n3IOsUBb 1/og6LRYMdhuwnC6gRrS+Rp43j89d89fTHCPkDQhMh8icQ8U+/cBzE/NQ97q2PpR6D 6BazdifTveXSm24GdIR0doZvUWMHOA8HqLgkqtCJkH+qAomr+3+ExiQl9pLTRT/ONJ 3qRGZ4Ag8XkoQ== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Takashi Iwai , Sasha Levin , alsa-devel@alsa-project.org Subject: [PATCH AUTOSEL 4.4 10/23] ALSA: sb: Fix potential double-free of CSP mixer elements Date: Fri, 9 Jul 2021 22:38:59 -0400 Message-Id: <20210710023912.3172972-10-sashal@kernel.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210710023912.3172972-1-sashal@kernel.org> References: <20210710023912.3172972-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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 2cc068be7d3b..90fa57ad14c0 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