From a9ba36a45dfac645a810c31ce15ab393b69d820a Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Wed, 26 Mar 2014 13:05:35 +0100 Subject: bochs: Fix bitmap offset calculation 32 bit truncation could let us access the wrong offset in the image. Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi Reviewed-by: Max Reitz Signed-off-by: Stefan Hajnoczi --- block/bochs.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'block/bochs.c') diff --git a/block/bochs.c b/block/bochs.c index a922782c1d..826ec1203c 100644 --- a/block/bochs.c +++ b/block/bochs.c @@ -186,8 +186,9 @@ static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num) return -1; /* not allocated */ } - bitmap_offset = s->data_offset + (512 * s->catalog_bitmap[extent_index] * - (s->extent_blocks + s->bitmap_blocks)); + bitmap_offset = s->data_offset + + (512 * (uint64_t) s->catalog_bitmap[extent_index] * + (s->extent_blocks + s->bitmap_blocks)); /* read in bitmap for current extent */ if (bdrv_pread(bs->file, bitmap_offset + (extent_offset / 8), -- cgit v1.2.1