From: Peter Lieven <pl@kamp.de>
Date: Tue, 24 Sep 2013 13:35:09 +0000 (+0200)
Subject: block/get_block_status: avoid segfault if there is no backing_hd
X-Git-Tag: v1.7.0-rc0~84^2~24
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=1f9db2243c1b987c834fe559a8e73b3178f50c2b;p=thirdparty%2Fqemu.git

block/get_block_status: avoid segfault if there is no backing_hd

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Peter Lieven <pl@kamp.de>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---

diff --git a/block.c b/block.c
index 9b444b34436..3366017aeac 100644
--- a/block.c
+++ b/block.c
@@ -3169,7 +3169,7 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
     if (!(ret & BDRV_BLOCK_DATA)) {
         if (bdrv_has_zero_init(bs)) {
             ret |= BDRV_BLOCK_ZERO;
-        } else {
+        } else if (bs->backing_hd) {
             BlockDriverState *bs2 = bs->backing_hd;
             int64_t length2 = bdrv_getlength(bs2);
             if (length2 >= 0 && sector_num >= (length2 >> BDRV_SECTOR_BITS)) {