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=-10.1 required=3.0 tests=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=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 D901BC432C0 for ; Fri, 22 Nov 2019 19:54:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A003E20704 for ; Fri, 22 Nov 2019 19:54:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574452468; bh=PgmHLsBySMD/WAnnTimLDpSm6vxvYajJ38PYZvgkUhw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=go8EqyMHr8UuILQAzUi+zGVi0BTOExv+egpXwvVIAWyyFXDIvJkOGn25Il/3bKXFX Nhy+slOaIpXoUFEQJMSpS+3L7QYIRR95kdYl009nA4z7234YuUf1NWSgKZLcqP+Fy7 Us0Nen8Osexm9yBHIvPpMPAKcCmXHvnMscoicjh4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727885AbfKVTy1 (ORCPT ); Fri, 22 Nov 2019 14:54:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:48474 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727255AbfKVTtP (ORCPT ); Fri, 22 Nov 2019 14:49:15 -0500 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 18CFF20748; Fri, 22 Nov 2019 19:49:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574452154; bh=PgmHLsBySMD/WAnnTimLDpSm6vxvYajJ38PYZvgkUhw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IPNz2N0BqMim9CviXVGJlJoM+CRMyIzygL7/DcKdeA1CJbwVWrM0SD/a+H4r143Tl W5PHpw0t3aejWUAefncqbCwFyyPZXC5pusxLFJiFcz6wPCnz0DIUY0qNyGHeZMreTA FuLJ3p7YRMvIrjcssuDnIpMTv43mDgaOtihyvQu0= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: paulhsia , Takashi Iwai , Sasha Levin , alsa-devel@alsa-project.org Subject: [PATCH AUTOSEL 4.19 12/25] ALSA: pcm: Fix stream lock usage in snd_pcm_period_elapsed() Date: Fri, 22 Nov 2019 14:48:45 -0500 Message-Id: <20191122194859.24508-12-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191122194859.24508-1-sashal@kernel.org> References: <20191122194859.24508-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: paulhsia [ Upstream commit f5cdc9d4003a2f66ea57b3edd3e04acc2b1a4439 ] If the nullity check for `substream->runtime` is outside of the lock region, it is possible to have a null runtime in the critical section if snd_pcm_detach_substream is called right before the lock. Signed-off-by: paulhsia Link: https://lore.kernel.org/r/20191112171715.128727-2-paulhsia@chromium.org Signed-off-by: Takashi Iwai Signed-off-by: Sasha Levin --- sound/core/pcm_lib.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c index 4e6110d778bd2..ad52126d3d22e 100644 --- a/sound/core/pcm_lib.c +++ b/sound/core/pcm_lib.c @@ -1797,11 +1797,14 @@ void snd_pcm_period_elapsed(struct snd_pcm_substream *substream) struct snd_pcm_runtime *runtime; unsigned long flags; - if (PCM_RUNTIME_CHECK(substream)) + if (snd_BUG_ON(!substream)) return; - runtime = substream->runtime; snd_pcm_stream_lock_irqsave(substream, flags); + if (PCM_RUNTIME_CHECK(substream)) + goto _unlock; + runtime = substream->runtime; + if (!snd_pcm_running(substream) || snd_pcm_update_hw_ptr0(substream, 1) < 0) goto _end; @@ -1812,6 +1815,7 @@ void snd_pcm_period_elapsed(struct snd_pcm_substream *substream) #endif _end: kill_fasync(&runtime->fasync, SIGIO, POLL_IN); + _unlock: snd_pcm_stream_unlock_irqrestore(substream, flags); } EXPORT_SYMBOL(snd_pcm_period_elapsed); -- 2.20.1