From patchwork Thu Jul 27 20:00:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 1813935 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=nongnu.org (client-ip=209.51.188.17; helo=lists.gnu.org; envelope-from=qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=redhat.com header.i=@redhat.com header.a=rsa-sha256 header.s=mimecast20190719 header.b=gYxvXK5Q; dkim-atps=neutral Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4RBhp12sXwz1yYc for ; Fri, 28 Jul 2023 06:15:05 +1000 (AEST) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1qP7BE-0000pX-Ga; Thu, 27 Jul 2023 16:01:48 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qP7Aw-0000ht-SN for qemu-devel@nongnu.org; Thu, 27 Jul 2023 16:01:33 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1qP7As-0002kF-B4 for qemu-devel@nongnu.org; Thu, 27 Jul 2023 16:01:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1690488081; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=z2XcPBhRtlf4rI2SPwIwNo+yPFXbfQemEPEauxege4k=; b=gYxvXK5Q0PEvxlPuJT14AI2y7toYOIWJ1f+bRwtIdqTz5y3eG+c98fKVb/lUBU/S/M1yhp HS9INDy+SeoY+pmU/MeWMpidADe0dNx8sFPWV0kE7ok0342xkjnTyrVE5UScNjdzcVb12N Ps2AKWgAndF+r7VFjHr4qosKEjHCELk= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-573-fKJLDxhsMWmBfi4aujgOSg-1; Thu, 27 Jul 2023 16:01:20 -0400 X-MC-Unique: fKJLDxhsMWmBfi4aujgOSg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1043F8028B2; Thu, 27 Jul 2023 20:01:18 +0000 (UTC) Received: from localhost (unknown [10.39.193.84]) by smtp.corp.redhat.com (Postfix) with ESMTP id 82E0F2166B25; Thu, 27 Jul 2023 20:01:17 +0000 (UTC) From: Stefan Hajnoczi To: qemu-devel@nongnu.org Cc: Stefan Hajnoczi , Kevin Wolf , Fam Zheng , qemu-block@nongnu.org, Richard Henderson , Hanna Reitz , Peter Maydell Subject: [PULL for-8.1 4/8] block: Fix pad_request's request restriction Date: Thu, 27 Jul 2023 16:00:54 -0400 Message-ID: <20230727200058.1071776-5-stefanha@redhat.com> In-Reply-To: <20230727200058.1071776-1-stefanha@redhat.com> References: <20230727200058.1071776-1-stefanha@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.6 Received-SPF: pass client-ip=170.10.129.124; envelope-from=stefanha@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=unavailable autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Hanna Czenczek bdrv_pad_request() relies on requests' lengths not to exceed SIZE_MAX, which bdrv_check_qiov_request() does not guarantee. bdrv_check_request32() however will guarantee this, and both of bdrv_pad_request()'s callers (bdrv_co_preadv_part() and bdrv_co_pwritev_part()) already run it before calling bdrv_pad_request(). Therefore, bdrv_pad_request() can safely call bdrv_check_request32() without expecting error, too. In effect, this patch will not change guest-visible behavior. It is a clean-up to tighten a condition to match what is guaranteed by our callers, and which exists purely to show clearly why the subsequent assertion (`assert(*bytes <= SIZE_MAX)`) is always true. Note there is a difference between the interfaces of bdrv_check_qiov_request() and bdrv_check_request32(): The former takes an errp, the latter does not, so we can no longer just pass &error_abort. Instead, we need to check the returned value. While we do expect success (because the callers have already run this function), an assert(ret == 0) is not much simpler than just to return an error if it occurs, so let us handle errors by returning them up the stack now. Reported-by: Peter Maydell Signed-off-by: Hanna Czenczek Message-id: 20230714085938.202730-1-hreitz@redhat.com Fixes: 18743311b829cafc1737a5f20bc3248d5f91ee2a ("block: Collapse padded I/O vecs exceeding IOV_MAX") Signed-off-by: Hanna Czenczek Signed-off-by: Stefan Hajnoczi --- block/io.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/block/io.c b/block/io.c index e8293d6b26..055fcf7438 100644 --- a/block/io.c +++ b/block/io.c @@ -1710,7 +1710,11 @@ static int bdrv_pad_request(BlockDriverState *bs, int sliced_niov; size_t sliced_head, sliced_tail; - bdrv_check_qiov_request(*offset, *bytes, *qiov, *qiov_offset, &error_abort); + /* Should have been checked by the caller already */ + ret = bdrv_check_request32(*offset, *bytes, *qiov, *qiov_offset); + if (ret < 0) { + return ret; + } if (!bdrv_init_padding(bs, *offset, *bytes, write, pad)) { if (padded) { @@ -1723,7 +1727,7 @@ static int bdrv_pad_request(BlockDriverState *bs, &sliced_head, &sliced_tail, &sliced_niov); - /* Guaranteed by bdrv_check_qiov_request() */ + /* Guaranteed by bdrv_check_request32() */ assert(*bytes <= SIZE_MAX); ret = bdrv_create_padded_qiov(bs, pad, sliced_iov, sliced_niov, sliced_head, *bytes);