From: Evgeny Budilovsky Date: Wed, 12 Jun 2013 11:06:30 +0000 (+0300) Subject: vmdk: Allow reading variable size descriptor files X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=0bed087df24c7b3fae366f239b9d150de3309416;p=qemu.git vmdk: Allow reading variable size descriptor files 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 --- diff --git a/block/vmdk.c b/block/vmdk.c index ee50a737c1..65ae0119c4 100644 --- a/block/vmdk.c +++ b/block/vmdk.c @@ -722,27 +722,40 @@ static int vmdk_open_desc_file(BlockDriverState *bs, int flags, int64_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, QDict *options, int flags)