The check on the max_table_size field not being larger than required is valid, and in accordance with the VHD spec. However, there have been VHD images encountered in the wild that have an out-of-spec max table size that is technically too large.
There is no issue in allowing this larger table size, as we also later verify that the computed size (used for the pagetable) is large enough to fit all sectors. In addition, max_table_entries is bounds checked against SIZE_MAX and INT_MAX. Remove the strict check, so that we can accomodate these sorts of images that are benignly out of spec. Reported-by: Stefan Hajnoczi <stefa...@redhat.com> Reported-by: Grant Wu <grant...@gmail.com> Signed-off-by: Jeff Cody <jc...@redhat.com> --- block/vpc.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/block/vpc.c b/block/vpc.c index 2e023d0..67ab376 100644 --- a/block/vpc.c +++ b/block/vpc.c @@ -350,10 +350,6 @@ static int vpc_open(BlockDriverState *bs, QDict *options, int flags, ret = -EINVAL; goto fail; } - if (s->max_table_entries > (VHD_MAX_SECTORS * 512) / s->block_size) { - ret = -EINVAL; - goto fail; - } computed_size = (uint64_t) s->max_table_entries * s->block_size; if (computed_size < bs->total_sectors * 512) { -- 1.9.3