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=-4.0 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no 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 D3366C43461 for ; Wed, 2 Sep 2020 15:48:05 +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 54111208C7 for ; Wed, 2 Sep 2020 15:48:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="VWCeGneO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 54111208C7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de 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 D92E11883; Wed, 2 Sep 2020 17:47:13 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz D92E11883 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1599061683; bh=ShIf8vb8jvo8nMD1g3OuM9DWbnhNOpSxQuTWcQARgk4=; h=Date:From:To:Subject:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=VWCeGneOh3wU+d2sUINslIJHyr3IeqWHZ17qU+2fEfsPWuHJxfmYq7R3Z72VHg9UX j0oc6A1ZsickmMtvPb8/DklmzgmLKX2iGAVoyLKPduicyUuTG0n8oOpts7O9zLSq7H 6N/NoXih2HTS+HKQY3OnusWtHSyNjm8CMYu1XZhg= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 4DB16F80268; Wed, 2 Sep 2020 17:47:11 +0200 (CEST) Received: by alsa1.perex.cz (Postfix, from userid 50401) id A80CAF8024A; Wed, 2 Sep 2020 17:47:09 +0200 (CEST) Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 691EEF80268 for ; Wed, 2 Sep 2020 17:46:58 +0200 (CEST) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 691EEF80268 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id A86E6AC5E; Wed, 2 Sep 2020 15:46:59 +0000 (UTC) Date: Wed, 02 Sep 2020 17:46:58 +0200 Message-ID: From: Takashi Iwai To: Al Viro Subject: Re: general protection fault in snd_ctl_release In-Reply-To: <20200902153530.GK1236603@ZenIV.linux.org.uk> References: <000000000000c15ee205ae4f2531@google.com> <20200902153530.GK1236603@ZenIV.linux.org.uk> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Cc: alsa-devel@alsa-project.org, maz@kernel.org, tiwai@suse.com, syzkaller-bugs@googlegroups.com, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, dan.carpenter@oracle.com 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" On Wed, 02 Sep 2020 17:35:30 +0200, Al Viro wrote: > > On Wed, Sep 02, 2020 at 05:22:00PM +0200, Takashi Iwai wrote: > > > Marc, Al, could you guys check this bug? > > That's racy; the first one should be get_file_rcu() instead of > file_count()+get_file(), the second is not needed at all (we > have the file pinned down by the caller). Yeah, that wasn't meant as a fix, of course :) > See vfs.git#work.epoll > for fix Thanks! I'll try to run with this fix. Takashi