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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 91A1EC6778A for ; Tue, 24 Jul 2018 07:01:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4CE8420874 for ; Tue, 24 Jul 2018 07:01:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4CE8420874 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388386AbeGXIF4 (ORCPT ); Tue, 24 Jul 2018 04:05:56 -0400 Received: from mx2.suse.de ([195.135.220.15]:48206 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2388264AbeGXIF4 (ORCPT ); Tue, 24 Jul 2018 04:05:56 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 0764FADE8; Tue, 24 Jul 2018 07:00:56 +0000 (UTC) Date: Tue, 24 Jul 2018 09:00:55 +0200 Message-ID: From: Takashi Iwai To: "DaeRyong Jeong" Cc: "Colin King" , , , "Kyungtae Kim" , "Byoungyoung Lee" , , , "LKML" Subject: Re: WARNING in port_delete In-Reply-To: References: <20180724033608.GA17607@dragonet> 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/26 (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 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 24 Jul 2018 05:59:56 +0200, DaeRyong Jeong wrote: > > I just realized that the crash has been spotted by Syzkaller a few days before. > (https://syzkaller.appspot.com/bug?id=3490860a465e6b39227c6906f0ef2d40ad4d5bb1) > > I'm CC'ing Syzkaller's mailing list. It's very likely a false-positive sanity check, and if so, nothing serious at all. We may simply remove two snd_BUG_ON() lines. But I'd love to have a C reproducer to confirm my understanding is correct... thanks, Takashi --- --- a/sound/core/seq/seq_ports.c +++ b/sound/core/seq/seq_ports.c @@ -272,9 +272,6 @@ static int port_delete(struct snd_seq_client *client, if (port->private_free) port->private_free(port->private_data); - snd_BUG_ON(port->c_src.count != 0); - snd_BUG_ON(port->c_dest.count != 0); - kfree(port); return 0; }