block/vhdx: check for offset overflow to bdrv_truncate()

VHDX uses uint64_t types for most offsets, following the VHDX spec.
However, bdrv_truncate() takes an int64_t value for the truncating
offset.  Check for overflow before calling bdrv_truncate().

While we are here, replace the bit shifting with QEMU_ALIGN_UP as well.

N.B.: For a compliant image this is not an issue, as the maximum VHDX
image size is defined per the spec to be 64TB.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/block/vhdx-log.c b/block/vhdx-log.c
index 2e26fd4..9597223 100644
--- a/block/vhdx-log.c
+++ b/block/vhdx-log.c
@@ -553,7 +553,11 @@ static int vhdx_log_flush(BlockDriverState *bs, BDRVVHDXState *s,
             new_file_size = desc_entries->hdr.last_file_offset;
             if (new_file_size % (1024*1024)) {
                 /* round up to nearest 1MB boundary */
-                new_file_size = ((new_file_size >> 20) + 1) << 20;
+                new_file_size = QEMU_ALIGN_UP(new_file_size, MiB);
+                if (new_file_size > INT64_MAX) {
+                    ret = -EINVAL;
+                    goto exit;
+                }
                 bdrv_truncate(bs->file, new_file_size, PREALLOC_MODE_OFF, NULL);
             }
         }