From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:38720) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XTyAn-0002xw-8k for qemu-devel@nongnu.org; Tue, 16 Sep 2014 15:12:27 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XTyAh-00037d-4A for qemu-devel@nongnu.org; Tue, 16 Sep 2014 15:12:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:48668) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XTyAg-000370-Sy for qemu-devel@nongnu.org; Tue, 16 Sep 2014 15:12:15 -0400 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s8GJC9JP028521 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Tue, 16 Sep 2014 15:12:10 -0400 From: Jeff Cody Date: Tue, 16 Sep 2014 15:12:06 -0400 Message-Id: <1410894726-21836-1-git-send-email-jcody@redhat.com> Subject: [Qemu-devel] [PATCH] block: vhdx - fix reading beyond pointer during image creation List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: kwolf@redhat.com, stefanha@redhat.com 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 --- block/vhdx.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/block/vhdx.c b/block/vhdx.c index 796b7bd..b52ec32 100644 --- a/block/vhdx.c +++ b/block/vhdx.c @@ -1407,6 +1407,12 @@ exit: return ret; } +#define VHDX_METADATA_ENTRY_BUFFER_SIZE \ + (sizeof(VHDXFileParameters) +\ + sizeof(VHDXVirtualDiskSize) +\ + sizeof(VHDXPage83Data) +\ + sizeof(VHDXVirtualDiskLogicalSectorSize) +\ + sizeof(VHDXVirtualDiskPhysicalSectorSize)) /* * Create the Metadata entries. @@ -1445,11 +1451,7 @@ 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); @@ -1530,7 +1532,7 @@ 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; } @@ -1725,7 +1727,6 @@ static int vhdx_create_new_region_table(BlockDriverState *bs, goto exit; } - exit: g_free(s); g_free(buffer); @@ -1876,7 +1877,6 @@ static int vhdx_create(const char *filename, QemuOpts *opts, Error **errp) } - delete_and_exit: bdrv_unref(bs); exit: -- 1.9.3