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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 9158DC433E0 for ; Wed, 13 Jan 2021 12:59:10 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 08FFC23406 for ; Wed, 13 Jan 2021 12:59:09 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 08FFC23406 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:47582 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kzfjv-0002XU-BI for qemu-devel@archiver.kernel.org; Wed, 13 Jan 2021 07:59:08 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:58144) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kzfiC-0001Wa-Hf for qemu-devel@nongnu.org; Wed, 13 Jan 2021 07:57:20 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:41969) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1kzfi5-0007Qi-S1 for qemu-devel@nongnu.org; Wed, 13 Jan 2021 07:57:20 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1610542632; 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: in-reply-to:in-reply-to:references:references; bh=UlSRGqVdbf+9Y7SgHVOkdaiWILTIdEFYCpq3ZaMmMdk=; b=c19JNMGQ67/LsB2X7G0EV5KvokC8dLRAXvVIQD9hAPqswETmFwkj2pEutfD2SVfJmWXk0O PfVAx98ndZOTmQA0eN6QZeeXSA6JiRyCyx/4HrCObCzNIrkN8lMAAHbtooMl1DI1PzuMvu sCZcwQQ8vTnwlxNOHDPKIASTIzvcaXQ= 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-381-9cfOmQYJMciEri4j-UUtrw-1; Wed, 13 Jan 2021 07:57:11 -0500 X-MC-Unique: 9cfOmQYJMciEri4j-UUtrw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 0DB22806661 for ; Wed, 13 Jan 2021 12:57:10 +0000 (UTC) Received: from blackfin.pond.sub.org (ovpn-112-172.ams2.redhat.com [10.36.112.172]) by smtp.corp.redhat.com (Postfix) with ESMTPS id D36BA5D9DC; Wed, 13 Jan 2021 12:57:09 +0000 (UTC) Received: by blackfin.pond.sub.org (Postfix, from userid 1000) id 501F111386A7; Wed, 13 Jan 2021 13:57:08 +0100 (CET) From: Markus Armbruster To: Eric Blake Subject: Re: [PATCH v3 1/7] net: Clarify early exit condition References: <20201223221102.390740-1-eblake@redhat.com> <20201223221102.390740-2-eblake@redhat.com> Date: Wed, 13 Jan 2021 13:57:08 +0100 In-Reply-To: <20201223221102.390740-2-eblake@redhat.com> (Eric Blake's message of "Wed, 23 Dec 2020 16:10:56 -0600") Message-ID: <87r1mp0zbv.fsf@dusky.pond.sub.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=armbru@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain Received-SPF: pass client-ip=216.205.24.124; envelope-from=armbru@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -29 X-Spam_score: -3.0 X-Spam_bar: --- X-Spam_report: (-3.0 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.25, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: Jason Wang , qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" Eric Blake writes: > On first glance, the loop in qmp_query_rx_filter() has early return > paths that could leak any allocation of filter_list from a previous > iteration. But on closer inspection, it is obvious that all of the > early exits are guarded by has_name, and that the bulk of the loop > body can be executed at most once if the user is filtering by name, > thus, any early exit coincides with an empty list. Add asserts to > make this obvious. > > Signed-off-by: Eric Blake > --- > net/net.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/net.c b/net/net.c > index e1035f21d183..e581c8a26868 100644 > --- a/net/net.c > +++ b/net/net.c > @@ -1211,6 +1211,7 @@ RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name, > if (nc->info->type != NET_CLIENT_DRIVER_NIC) { > if (has_name) { > error_setg(errp, "net client(%s) isn't a NIC", name); > + assert(!filter_list); > return NULL; > } > continue; > @@ -1236,6 +1237,7 @@ RxFilterInfoList *qmp_query_rx_filter(bool has_name, const char *name, > } else if (has_name) { > error_setg(errp, "net client(%s) doesn't support" > " rx-filter querying", name); > + assert(!filter_list); > return NULL; > } Reviewed-by: Markus Armbruster