[PATCH] block vvfat.c fix leak when failure occurs

[Daniella Lee]

Based on your suggestions. I made a new patch which contians:
1.format detection
2.replace calloc with g_malloc0 in enable_write_target function
3.use g_free without null pointer detection in vvfat_open function
4.delete line "ret = 0", use return ret directly in vvfat_open function


Signed-off-by: Daniella Lee <daniellalee111@gmail.com>
---
 block/vvfat.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/block/vvfat.c b/block/vvfat.c
index 05e78e3c27..5dacc6cfac 100644
--- a/block/vvfat.c
+++ b/block/vvfat.c
@@ -1279,8 +1279,18 @@ static int vvfat_open(BlockDriverState *bs, QDict 
*options, int flags,
 
     qemu_co_mutex_init(&s->lock);
 
-    ret = 0;
+    qemu_opts_del(opts);
+
+    return 0;
+
 fail:
+    g_free(s->qcow_filename);
+    s->qcow_filename = NULL;
+    g_free(s->cluster_buffer);
+    s->cluster_buffer = NULL;
+    g_free(s->used_clusters);
+    s->used_clusters = NULL;
+
     qemu_opts_del(opts);
     return ret;
 }
@@ -3118,7 +3128,7 @@ static int enable_write_target(BlockDriverState *bs, 
Error **errp)
     int size = sector2cluster(s, s->sector_count);
     QDict *options;
 
-    s->used_clusters = calloc(size, 1);
+    s->used_clusters = g_malloc0(size);
 
     array_init(&(s->commits), sizeof(commit_t));
 
@@ -3166,8 +3176,6 @@ static int enable_write_target(BlockDriverState *bs, 
Error **errp)
     return 0;
 
 err:
-    g_free(s->qcow_filename);
-    s->qcow_filename = NULL;
     return ret;
 }
 
-- 
2.17.1