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spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:40604 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ljj6x-0001BU-3F for qemu-devel@archiver.kernel.org; Thu, 20 May 2021 09:53:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:52644) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ljj5d-0007eY-PA for qemu-devel@nongnu.org; Thu, 20 May 2021 09:51:53 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:21829) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ljj5b-0002zc-PL for qemu-devel@nongnu.org; Thu, 20 May 2021 09:51:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1621518710; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1ttWY/Nnr3cCN9m/I1t5hiiG+jIQMvTIfnx/PEc/p5I=; b=Fz50MxckWz1Dgl1bO/ZkfhnMqqpxFq6sVe6WXwZOLKoCDznJwYWmgrXtjuuFlpwjqfmHqB n6O3zZ5rWC9XhtlLhhcuIWoS6oPfvvEZWxMwsZnC6EB2b1V8MSlNhVSiQKurd1Qsa9hQQ+ 8Ker5Q8vWN7nViVnPVwl6H3DRss2FOg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-62-1DILQmTPPT-0ecAGWOUwMw-1; Thu, 20 May 2021 09:51:47 -0400 X-MC-Unique: 1DILQmTPPT-0ecAGWOUwMw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2FDF28015C6; Thu, 20 May 2021 13:51:46 +0000 (UTC) Received: from dresden.str.redhat.com (ovpn-114-95.ams2.redhat.com [10.36.114.95]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 2DE7D19C71; Thu, 20 May 2021 13:51:45 +0000 (UTC) Subject: Re: [PULL 03/19] monitor: hmp_qemu_io: acquire aio contex, fix crash To: Peter Maydell References: <20210514164514.1057680-1-mreitz@redhat.com> <20210514164514.1057680-4-mreitz@redhat.com> From: Max Reitz Message-ID: Date: Thu, 20 May 2021 15:51:43 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=mreitz@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=mreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -31 X-Spam_score: -3.2 X-Spam_bar: --- X-Spam_report: (-3.2 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.39, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, NICE_REPLY_A=-0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Kevin Wolf , QEMU Developers , Qemu-block Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 20.05.21 15:44, Peter Maydell wrote: > On Fri, 14 May 2021 at 17:45, Max Reitz wrote: >> >> From: Vladimir Sementsov-Ogievskiy > > Hi; Coverity complains about this code (CID 1453194): > >> diff --git a/qemu-io.c b/qemu-io.c >> index bf902302e9..57f07501df 100644 >> --- a/qemu-io.c >> +++ b/qemu-io.c >> @@ -411,6 +411,19 @@ static void prep_fetchline(void *opaque) >> *fetchable= 1; >> } >> >> +static int do_qemuio_command(const char *cmd) >> +{ >> + int ret; >> + AioContext *ctx = >> + qemuio_blk ? blk_get_aio_context(qemuio_blk) : qemu_get_aio_context(); > > Here we check whether qemuio_blk is NULL... > >> + >> + aio_context_acquire(ctx); >> + ret = qemuio_command(qemuio_blk, cmd); > > ...but here we pass it to qemuio_command(), which assumes it must > be non-NULL (via calling command() which calls blk_is_available()). > > Bug, or false positive ? It’s a false positive, Vladimir has sent a patch to silence Coverity: https://lists.nongnu.org/archive/html/qemu-block/2021-05/msg00853.html Max