From bf5f0cf5d819cce45dd578a19386d8b60022654f Mon Sep 17 00:00:00 2001 From: Vladimir Sementsov-Ogievskiy Date: Mon, 11 Mar 2019 21:51:45 +0300 Subject: [PATCH] block/qcow2-bitmap: Don't check size for IN_USE bitmap We are going to allow image resize when there are persistent bitmaps. It may lead to appearing of inconsistent bitmaps (IN_USE=1) with inconsistent size. But we still want to load them as inconsistent. Signed-off-by: Vladimir Sementsov-Ogievskiy Message-id: 20190311185147.52309-3-vsementsov@virtuozzo.com Signed-off-by: John Snow --- block/qcow2-bitmap.c | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c index 885f36c2ab..92cef1cfd4 100644 --- a/block/qcow2-bitmap.c +++ b/block/qcow2-bitmap.c @@ -462,10 +462,25 @@ static int check_dir_entry(BlockDriverState *bs, Qcow2BitmapDirEntry *entry) return len; } - fail = (phys_bitmap_bytes > BME_MAX_PHYS_SIZE) || - (len > ((phys_bitmap_bytes * 8) << entry->granularity_bits)); + if (phys_bitmap_bytes > BME_MAX_PHYS_SIZE) { + return -EINVAL; + } - return fail ? -EINVAL : 0; + if (!(entry->flags & BME_FLAG_IN_USE) && + (len > ((phys_bitmap_bytes * 8) << entry->granularity_bits))) + { + /* + * We've loaded a valid bitmap (IN_USE not set) or we are going to + * store a valid bitmap, but the allocated bitmap table size is not + * enough to store this bitmap. + * + * Note, that it's OK to have an invalid bitmap with invalid size due + * to a bitmap that was not correctly saved after image resize. + */ + return -EINVAL; + } + + return 0; } static inline void bitmap_directory_to_be(uint8_t *dir, size_t size)