[Qemu-block] [PATCH for 2.10 07/35] qcow2: fix null pointer dereference

[Philippe Mathieu-Daudé]

If find_bitmap_by_name() fails we have bm=NULL and go to the 'fail' label, then
call bitmap_free(bm) which does g_free(bm->name) with bm=NULL...

Clang's scan-build-5.0 output:
block/qcow2-bitmap.c:492:12: warning: Access to field 'name' results in a 
dereference of a null pointer (loaded from variable 'bm')
    g_free(bm->name);
           ^~~~~~~~

Reported-by: Clang Static Analyzer
Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
---
 block/qcow2-bitmap.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/block/qcow2-bitmap.c b/block/qcow2-bitmap.c
index fe72df5057..2fd75781ce 100644
--- a/block/qcow2-bitmap.c
+++ b/block/qcow2-bitmap.c
@@ -1259,7 +1259,7 @@ void 
qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 
     bm = find_bitmap_by_name(bm_list, name);
     if (bm == NULL) {
-        goto fail;
+        goto fail_list;
     }
 
     QSIMPLEQ_REMOVE(bm_list, bm, Qcow2Bitmap, entry);
@@ -1274,6 +1274,7 @@ void 
qcow2_remove_persistent_dirty_bitmap(BlockDriverState *bs,
 
 fail:
     bitmap_free(bm);
+fail_list:
     bitmap_list_free(bm_list);
 }
 
-- 
2.13.3