From patchwork Thu Oct 10 15:33:27 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Peter Lieven X-Patchwork-Id: 1174685 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (mailfrom) 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: ozlabs.org; dmarc=none (p=none dis=none) header.from=kamp.de 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 ozlabs.org (Postfix) with ESMTPS id 46pwry6FhZz9sDQ for ; Fri, 11 Oct 2019 03:04:49 +1100 (AEDT) Received: from localhost ([::1]:41668 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iIavm-0007Pq-VV for incoming@patchwork.ozlabs.org; Thu, 10 Oct 2019 12:04:47 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:34374) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iIaRh-0006GZ-QY for qemu-devel@nongnu.org; Thu, 10 Oct 2019 11:33:43 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iIaRg-000789-21 for qemu-devel@nongnu.org; Thu, 10 Oct 2019 11:33:41 -0400 Received: from kerio.kamp.de ([195.62.97.192]:43649) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iIaRf-00075E-Nh for qemu-devel@nongnu.org; Thu, 10 Oct 2019 11:33:39 -0400 X-Footer: a2FtcC5kZQ== Received: from submission.kamp.de ([195.62.97.28]) by kerio.kamp.de with ESMTPS (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256 bits)) for qemu-devel@nongnu.org; Thu, 10 Oct 2019 17:33:26 +0200 Received: (qmail 43439 invoked from network); 10 Oct 2019 15:33:29 -0000 Received: from lieven-pc.kamp-intra.net (HELO lieven-pc) (relay@kamp.de@::ffff:172.21.12.60) by submission.kamp.de with ESMTPS (DHE-RSA-AES256-GCM-SHA384 encrypted) ESMTPA; 10 Oct 2019 15:33:29 -0000 Received: by lieven-pc (Postfix, from userid 1060) id 86FAC13D878; Thu, 10 Oct 2019 17:33:29 +0200 (CEST) From: Peter Lieven To: qemu-block@nongnu.org Subject: [RESEND PATCH V4] block/vhdx: add check for truncated image files Date: Thu, 10 Oct 2019 17:33:27 +0200 Message-Id: <20191010153327.18696-1-pl@kamp.de> X-Mailer: git-send-email 2.17.1 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 195.62.97.192 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: kwolf@redhat.com, codyprime@gmail.com, Peter Lieven , qemu-devel@nongnu.org, mreitz@redhat.com, jhf@kamp.de Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: "Qemu-devel" qemu is currently not able to detect truncated vhdx image files. Add a basic check if all allocated blocks are reachable at open and report all errors during bdrv_co_check. Signed-off-by: Peter Lieven --- V4: - allow partial last blocks [Kevin] - report offsets in error messages [Kevin] - check for start and end offset after eof V3: - check for bdrv_getlength failure [Kevin] - use uint32_t for i [Kevin] - check for BAT entry overflow [Kevin] - break on !errcnt in second check V2: - add error reporting [Kevin] - use bdrv_getlength instead of bdrv_get_allocated_file_size [Kevin] - factor out BAT entry check and add error reporting for region overlaps - already check on vhdx_open block/vhdx.c | 120 +++++++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 103 insertions(+), 17 deletions(-) diff --git a/block/vhdx.c b/block/vhdx.c index 6a09d0a55c..371f226286 100644 --- a/block/vhdx.c +++ b/block/vhdx.c @@ -24,6 +24,7 @@ #include "qemu/option.h" #include "qemu/crc32c.h" #include "qemu/bswap.h" +#include "qemu/error-report.h" #include "vhdx.h" #include "migration/blocker.h" #include "qemu/uuid.h" @@ -235,6 +236,9 @@ static int vhdx_region_check(BDRVVHDXState *s, uint64_t start, uint64_t length) end = start + length; QLIST_FOREACH(r, &s->regions, entries) { if (!((start >= r->end) || (end <= r->start))) { + error_report("VHDX region %" PRIu64 "-%" PRIu64 " overlaps with " + "region %" PRIu64 "-%." PRIu64, start, end, r->start, + r->end); ret = -EINVAL; goto exit; } @@ -877,6 +881,95 @@ static void vhdx_calc_bat_entries(BDRVVHDXState *s) } +static int vhdx_check_bat_entries(BlockDriverState *bs, int *errcnt) +{ + BDRVVHDXState *s = bs->opaque; + int64_t image_file_size = bdrv_getlength(bs->file->bs); + uint64_t payblocks = s->chunk_ratio; + uint64_t i; + int ret = 0; + + if (image_file_size < 0) { + error_report("Could not determinate VHDX image file size."); + return image_file_size; + } + + for (i = 0; i < s->bat_entries; i++) { + if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == + PAYLOAD_BLOCK_FULLY_PRESENT) { + uint64_t offset = s->bat[i] & VHDX_BAT_FILE_OFF_MASK; + /* + * Allow that the last block exists only partially. The VHDX spec + * states that the image file can only grow in blocksize increments, + * but QEMU created images with partial last blocks in the past. + */ + uint32_t block_length = MIN(s->block_size, + bs->total_sectors * BDRV_SECTOR_SIZE - i * s->block_size); + /* + * Check for BAT entry overflow. + */ + if (offset > INT64_MAX - s->block_size) { + error_report("VHDX BAT entry %" PRIu64 " offset overflow.", i); + ret = -EINVAL; + if (!errcnt) { + break; + } + (*errcnt)++; + } + /* + * Check if fully allocated BAT entries do not reside after + * end of the image file. + */ + if (offset >= image_file_size) { + error_report("VHDX BAT entry %" PRIu64 " start offset %" PRIu64 + " points after end of file (%" PRIi64 "). Image" + " has probably been truncated.", + i, offset, image_file_size); + ret = -EINVAL; + if (!errcnt) { + break; + } + (*errcnt)++; + } else if (offset + block_length > image_file_size) { + error_report("VHDX BAT entry %" PRIu64 " end offset %" PRIu64 + " points after end of file (%" PRIi64 "). Image" + " has probably been truncated.", + i, offset + block_length - 1, image_file_size); + ret = -EINVAL; + if (!errcnt) { + break; + } + (*errcnt)++; + } + + /* + * verify populated BAT field file offsets against + * region table and log entries + */ + if (payblocks--) { + /* payload bat entries */ + int ret2; + ret2 = vhdx_region_check(s, offset, s->block_size); + if (ret2 < 0) { + ret = -EINVAL; + if (!errcnt) { + break; + } + (*errcnt)++; + } + } else { + payblocks = s->chunk_ratio; + /* + * Once differencing files are supported, verify sector bitmap + * blocks here + */ + } + } + } + + return ret; +} + static void vhdx_close(BlockDriverState *bs) { BDRVVHDXState *s = bs->opaque; @@ -981,25 +1074,15 @@ static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, goto fail; } - uint64_t payblocks = s->chunk_ratio; - /* endian convert, and verify populated BAT field file offsets against - * region table and log entries */ + /* endian convert populated BAT field entires */ for (i = 0; i < s->bat_entries; i++) { s->bat[i] = le64_to_cpu(s->bat[i]); - if (payblocks--) { - /* payload bat entries */ - if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == - PAYLOAD_BLOCK_FULLY_PRESENT) { - ret = vhdx_region_check(s, s->bat[i] & VHDX_BAT_FILE_OFF_MASK, - s->block_size); - if (ret < 0) { - goto fail; - } - } - } else { - payblocks = s->chunk_ratio; - /* Once differencing files are supported, verify sector bitmap - * blocks here */ + } + + if (!(flags & BDRV_O_CHECK)) { + ret = vhdx_check_bat_entries(bs, NULL); + if (ret < 0) { + goto fail; } } @@ -2072,6 +2155,9 @@ static int coroutine_fn vhdx_co_check(BlockDriverState *bs, if (s->log_replayed_on_open) { result->corruptions_fixed++; } + + vhdx_check_bat_entries(bs, &result->corruptions); + return 0; }