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=-15.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 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 3B69DC433C1 for ; Mon, 22 Mar 2021 10:05:37 +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 946CB61927 for ; Mon, 22 Mar 2021 10:05:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 946CB61927 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]:48072 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lOHRG-0005QA-TE for qemu-devel@archiver.kernel.org; Mon, 22 Mar 2021 06:05:34 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:53488) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lOHOQ-0003Sy-Dr for qemu-devel@nongnu.org; Mon, 22 Mar 2021 06:02:38 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:42300) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lOHOJ-0007e1-PN for qemu-devel@nongnu.org; Mon, 22 Mar 2021 06:02:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1616407350; 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=kl3ufcYg6H8cidp1EOT8XNlIIyH+xI6dlLyTCOOjCl4=; b=PTENjQSFEPBYQaw+9p4OinzuYUPuH1uBPsPzxDTDvcn+aaOUqtvMm5CPagNZuzvjHxTtj/ dAG8HgLKJV49Wvy3NmVezR4M8JsehPMEoSwRRnjEprXmJJ+Dd1595dQ36C2qRWhv4k48Tg 6eJgywCKHj3EiJ4AOci2wTrm0vA/DzY= 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-376-PpGpYpZePQOE1z2Awe7Qug-1; Mon, 22 Mar 2021 06:02:26 -0400 X-MC-Unique: PpGpYpZePQOE1z2Awe7Qug-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id B4CA8881D65; Mon, 22 Mar 2021 10:02:24 +0000 (UTC) Received: from dresden.str.redhat.com (ovpn-114-196.ams2.redhat.com [10.36.114.196]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5EAC59CA0; Mon, 22 Mar 2021 10:02:23 +0000 (UTC) Subject: Re: [PATCH 2/2] hw/block/nvme: fix resource leak in nvme_format_ns To: Klaus Jensen , qemu-devel@nongnu.org References: <20210322061951.186748-1-its@irrelevant.dk> <20210322061951.186748-3-its@irrelevant.dk> From: Max Reitz Message-ID: <75eb366b-32d9-ba67-971b-e5993f5ae192@redhat.com> Date: Mon, 22 Mar 2021 11:02:21 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <20210322061951.186748-3-its@irrelevant.dk> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 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=63.128.21.124; envelope-from=mreitz@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, 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=-0.01, RCVD_IN_MSPIKE_WL=-0.01, 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: Keith Busch , Kevin Wolf , qemu-block@nongnu.org, Klaus Jensen Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 22.03.21 07:19, Klaus Jensen wrote: > From: Klaus Jensen > > In nvme_format_ns(), if the namespace is of zero size (which might be > useless, but not invalid), the `count` variable will leak. Fix this by > returning early in that case. When looking at the Coverity report, something else caught my eye: As far as I’m aware, blk_aio_pwrite_zeroes() may invoke the CB before returning (if blk_do_pwritev_part() returns without yielding). I don’t think that will happen with real hardware (who knows, though), but it should be possible to see with the null-co block driver. nvme_format_ns() doesn’t quite look like it takes that into account. For example, because *count starts at 1 and is decremented after the while (len) loop, all nvme_aio_format_cb() invocations (if they are invoked before their blk_aio_pwrite_zeroes() returns) will see *count == 2, and thus not free it, or call nvme_enqueue_req_completion(). I don’t know whether the latter is problematic, but not freeing `count` doesn’t seem right. Perhaps this could be addressed by adding a condition to the `(*count)--` to see whether `(*count)-- == 1` (or rather `--(*count) == 0`), which would indicate that there are no AIO functions still in flight? Max > Reported-by: Coverity (CID 1451082) > Fixes: dc04d25e2f3f ("hw/block/nvme: add support for the format nvm command") > Signed-off-by: Klaus Jensen > --- > hw/block/nvme.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/hw/block/nvme.c b/hw/block/nvme.c > index 6842b01ab58b..dad275971a84 100644 > --- a/hw/block/nvme.c > +++ b/hw/block/nvme.c > @@ -4984,6 +4984,11 @@ static uint16_t nvme_format_ns(NvmeCtrl *n, NvmeNamespace *ns, uint8_t lbaf, > ns->status = NVME_FORMAT_IN_PROGRESS; > > len = ns->size; > + > + if (!len) { > + return NVME_SUCCESS; > + } > + > offset = 0; > > count = g_new(int, 1); >