From e91a8b2fef92e7d31290e785a35f85a503fa1356 Mon Sep 17 00:00:00 2001 From: Jeff Cody Date: Tue, 16 Sep 2014 15:12:06 -0400 Subject: block: vhdx - fix reading beyond pointer during image creation In vhdx_create_metadata(), we allocate 40 bytes to entry_buffer for the various metadata table entries. However, we write out 64kB from that buffer into the new file. Only write out the correct 40 bytes. Signed-off-by: Jeff Cody Reviewed-by: Markus Armbruster Signed-off-by: Stefan Hajnoczi --- block/vhdx.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/block/vhdx.c b/block/vhdx.c index d9aa2c1..22a4fb8 100644 --- a/block/vhdx.c +++ b/block/vhdx.c @@ -1408,6 +1408,12 @@ exit: return ret; } +#define VHDX_METADATA_ENTRY_BUFFER_SIZE \ + (sizeof(VHDXFileParameters) +\ + sizeof(VHDXVirtualDiskSize) +\ + sizeof(VHDXPage83Data) +\ + sizeof(VHDXVirtualDiskLogicalSectorSize) +\ + sizeof(VHDXVirtualDiskPhysicalSectorSize)) /* * Create the Metadata entries. @@ -1446,11 +1452,7 @@ static int vhdx_create_new_metadata(BlockDriverState *bs, VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size; VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size; - entry_buffer = g_malloc0(sizeof(VHDXFileParameters) + - sizeof(VHDXVirtualDiskSize) + - sizeof(VHDXPage83Data) + - sizeof(VHDXVirtualDiskLogicalSectorSize) + - sizeof(VHDXVirtualDiskPhysicalSectorSize)); + entry_buffer = g_malloc0(VHDX_METADATA_ENTRY_BUFFER_SIZE); mt_file_params = entry_buffer; offset += sizeof(VHDXFileParameters); @@ -1531,7 +1533,7 @@ static int vhdx_create_new_metadata(BlockDriverState *bs, } ret = bdrv_pwrite(bs, metadata_offset + (64 * KiB), entry_buffer, - VHDX_HEADER_BLOCK_SIZE); + VHDX_METADATA_ENTRY_BUFFER_SIZE); if (ret < 0) { goto exit; } @@ -1726,7 +1728,6 @@ static int vhdx_create_new_region_table(BlockDriverState *bs, goto exit; } - exit: g_free(s); g_free(buffer); @@ -1877,7 +1878,6 @@ static int vhdx_create(const char *filename, QemuOpts *opts, Error **errp) } - delete_and_exit: bdrv_unref(bs); exit: -- cgit v1.1