From 99b0f8ab78ba68a9b25e201d270684b587fbd2d4 Mon Sep 17 00:00:00 2001 Message-Id: <99b0f8ab78ba68a9b25e201d270684b587fbd2d4.1376387172.git.minovotn@redhat.com> In-Reply-To: References: From: Fam Zheng Date: Thu, 8 Aug 2013 06:09:41 +0200 Subject: [PATCH 11/13] vmdk: Allow reading variable size descriptor files RH-Author: Fam Zheng Message-id: <1375942181-5262-12-git-send-email-famz@redhat.com> Patchwork-id: 53076 O-Subject: [RHEL-6.5 qemu-kvm PATCH 11/11] vmdk: Allow reading variable size descriptor files Bugzilla: 994804 RH-Acked-by: Kevin Wolf RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Jeffrey Cody From: Evgeny Budilovsky the hard-coded 2k buffer on the stack won't allow reading big descriptor files which can be generated when storing big images. For example 500G vmdk splitted to 2G chunks. Signed-off-by: Evgeny Budilovsky Reviewed-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf (cherry picked from commit 0bed087df24c7b3fae366f239b9d150de3309416) Signed-off-by: Fam Zheng --- block/vmdk.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) Signed-off-by: Michal Novotny --- block/vmdk.c | 27 ++++++++++++++++++++------- 1 file changed, 20 insertions(+), 7 deletions(-) diff --git a/block/vmdk.c b/block/vmdk.c index a4e37c2..be9f1c5 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -765,27 +765,40 @@ static int vmdk_open_desc_file(BlockDriverState *bs, int flags, uint64_t desc_offset) { int ret; - char buf[2048]; + char *buf = NULL; char ct[128]; BDRVVmdkState *s = bs->opaque; + int64_t size; - ret = bdrv_pread(bs->file, desc_offset, buf, sizeof(buf)); + size = bdrv_getlength(bs->file); + if (size < 0) { + return -EINVAL; + } + + size = MIN(size, 1 << 20); /* avoid unbounded allocation */ + buf = g_malloc0(size + 1); + + ret = bdrv_pread(bs->file, desc_offset, buf, size); if (ret < 0) { - return ret; + goto exit; } - buf[2047] = '\0'; if (vmdk_parse_description(buf, "createType", ct, sizeof(ct))) { - return -EMEDIUMTYPE; + ret = -EMEDIUMTYPE; + goto exit; } if (strcmp(ct, "monolithicFlat") && strcmp(ct, "twoGbMaxExtentSparse") && strcmp(ct, "twoGbMaxExtentFlat")) { fprintf(stderr, "VMDK: Not supported image type \"%s\""".\n", ct); - return -ENOTSUP; + ret = -ENOTSUP; + goto exit; } s->desc_offset = 0; - return vmdk_parse_extents(buf, bs, bs->file->filename); + ret = vmdk_parse_extents(buf, bs, bs->file->filename); +exit: + g_free(buf); + return ret; } static int vmdk_open(BlockDriverState *bs, int flags) -- 1.7.11.7