[Qemu-devel] [PATCH 1/2] block: Detect multiplication overflow in bdrv_getlength

[Fam Zheng <famz@redhat.com>]

Bogus image may have a large total_sectors that will overflow the
multiplication. For cleanness, fix the return code so the error message
will be meaningful.

Reported-by: Richard W.M. Jones <rjones@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
---
 block.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block.c b/block.c
index 7904098..5ee3fdf 100644
--- a/block.c
+++ b/block.c
@@ -2330,6 +2330,7 @@ int64_t bdrv_getlength(BlockDriverState *bs)
 {
     int64_t ret = bdrv_nb_sectors(bs);
 
+    ret = (int64_t)(ret * BDRV_SECTOR_SIZE) < 0 ? -EFBIG : ret;
     return ret < 0 ? ret : ret * BDRV_SECTOR_SIZE;
 }
 
-- 
2.4.0