[Qemu-devel] [PATCH v3 3/9] block: Handle error of bdrv_getlength in bdrv_create_dirty_bitmap

[Fam Zheng]

bdrv_getlength could fail, check the return value before using it.

Signed-off-by: Fam Zheng <f...@redhat.com>
Reviewed-by: Benoit Canet <ben...@irqsave.net>
---
 block.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/block.c b/block.c
index d240f1e..e32da75 100644
--- a/block.c
+++ b/block.c
@@ -5097,7 +5097,12 @@ BdrvDirtyBitmap 
*bdrv_create_dirty_bitmap(BlockDriverState *bs,
     }
     granularity >>= BDRV_SECTOR_BITS;
     assert(granularity);
-    bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS);
+    bitmap_size = bdrv_getlength(bs);
+    if (bitmap_size < 0) {
+        error_setg(errp, "could not get length of device");
+        return NULL;
+    }
+    bitmap_size >>= BDRV_SECTOR_BITS;
     bitmap = g_malloc0(sizeof(BdrvDirtyBitmap));
     bitmap->bitmap = hbitmap_alloc(bitmap_size, ffs(granularity) - 1);
     if (name) {
-- 
1.9.0