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block/vpc: make checks on max table size a bit more lax 

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 <stefanha@redhat.com>
Reported-by: Grant Wu <grantwwu@gmail.com>
Signed-off-by: Jeff Cody <jcody@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Jeff Cody 2016-03-22 23:33:42 -04:00 committed by Kevin Wolf
parent c23fb11bbb
commit 66176fc6a7
1 changed files with 0 additions and 4 deletions
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4
block/vpc.c
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@ -351,10 +351,6 @@ 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) {