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=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,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 A0C06C43464 for ; Fri, 18 Sep 2020 02:07:39 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B33F4239A1 for ; Fri, 18 Sep 2020 02:07:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="tMbjCVa4"; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="xRcKCo1z" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B33F4239A1 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id 3A75516DB; Fri, 18 Sep 2020 04:06:47 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 3A75516DB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1600394857; bh=xR3JxS7dReW87Az2A8LeOTHlQ0QfKGc3fI+787wEz9Q=; h=From:To:Subject:Date:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=tMbjCVa4RzN3ookBcL4sEHTL/08094k3/LA2Exy3EA6Ldxnrz7T1SyC30UA4G+5eD sRdJPnrhagHRZ4/rs5gKmfeGfEAx76MVpfSqhTQF5xL3xhuWAunVR3HGnRx4vd07ff mwshb9ahVLWj0BZVt8QnQKU688xmd8GdQClS1Gq4= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id A1C54F80150; Fri, 18 Sep 2020 04:06:43 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id 1E65DF802BE; Fri, 18 Sep 2020 04:06:42 +0200 (CEST) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 82FB3F8012D for ; Fri, 18 Sep 2020 04:06:39 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 82FB3F8012D Authentication-Results: alsa1.perex.cz; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="xRcKCo1z" Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5F3BC238A1; Fri, 18 Sep 2020 02:06:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1600394798; bh=xR3JxS7dReW87Az2A8LeOTHlQ0QfKGc3fI+787wEz9Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xRcKCo1zfQpEJ0vOb8FUUiiEeetZtoF9MoW5/W3sdlnjaziEo336cZ56OTiAHTcGF 2uNYa4ZK63co6xy2hf86t8ZinvHt9s4ZeLfVUvkniPOLS1BTDPE7cjlWDnVQLzAy/0 gBThZ60xD5fgqOQ/70C9m5Tc38suj+XqfBnHw8V8= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 267/330] ALSA: hda: Fix potential race in unsol event handler Date: Thu, 17 Sep 2020 22:00:07 -0400 Message-Id: <20200918020110.2063155-267-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200918020110.2063155-1-sashal@kernel.org> References: <20200918020110.2063155-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Cc: Takashi Iwai , Sasha Levin , alsa-devel@alsa-project.org X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" From: Takashi Iwai [ Upstream commit c637fa151259c0f74665fde7cba5b7eac1417ae5 ] The unsol event handling code has a loop retrieving the read/write indices and the arrays without locking while the append to the array may happen concurrently. This may lead to some inconsistency. Although there hasn't been any proof of this bad results, it's still safer to protect the racy accesses. This patch adds the spinlock protection around the unsol handling loop for addressing it. Here we take bus->reg_lock as the writer side snd_hdac_bus_queue_event() is also protected by that lock. Link: https://lore.kernel.org/r/20200516062556.30951-1-tiwai@suse.de Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/hda/hdac_bus.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/sound/hda/hdac_bus.c b/sound/hda/hdac_bus.c index 8f19876244ebe..53be2cac98e7c 100644 --- a/sound/hda/hdac_bus.c +++ b/sound/hda/hdac_bus.c @@ -158,6 +158,7 @@ static void snd_hdac_bus_process_unsol_events(struct work_struct *work) struct hdac_driver *drv; unsigned int rp, caddr, res; + spin_lock_irq(&bus->reg_lock); while (bus->unsol_rp != bus->unsol_wp) { rp = (bus->unsol_rp + 1) % HDA_UNSOL_QUEUE_SIZE; bus->unsol_rp = rp; @@ -169,10 +170,13 @@ static void snd_hdac_bus_process_unsol_events(struct work_struct *work) codec = bus->caddr_tbl[caddr & 0x0f]; if (!codec || !codec->dev.driver) continue; + spin_unlock_irq(&bus->reg_lock); drv = drv_to_hdac_driver(codec->dev.driver); if (drv->unsol_event) drv->unsol_event(codec, res); + spin_lock_irq(&bus->reg_lock); } + spin_unlock_irq(&bus->reg_lock); } /** -- 2.25.1