[Qemu-devel] [PATCH for-2.0 13/47] bochs: Fix bitmap offset calculation

[Stefan Hajnoczi]

From: Kevin Wolf <address@hidden>

32 bit truncation could let us access the wrong offset in the image.

Signed-off-by: Kevin Wolf <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
---
 block/bochs.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/block/bochs.c b/block/bochs.c
index a922782..826ec12 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),
-- 
1.8.5.3