[v3] parallels: Add full dirty bitmap support

[PATCH v3 01/21] parallels: Set s->used_bmap to NULL in parallels_free_used_bitmap()

Posted by Alexander Ivanov 2 years, 1 month ago

After used bitmap freeng s->used_bmap points to the freed memory. If we try
to free used bitmap one more time it leads to double free error.

Set s->used_bmap to NULL to exclude double free error.

Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
---
 block/parallels.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/block/parallels.c b/block/parallels.c
index 1d695ce7fb..01a61a4ebd 100644
--- a/block/parallels.c
+++ b/block/parallels.c
@@ -245,6 +245,7 @@ static void parallels_free_used_bitmap(BlockDriverState *bs)
     BDRVParallelsState *s = bs->opaque;
     s->used_bmap_size = 0;
     g_free(s->used_bmap);
+    s->used_bmap = NULL;
 }
 
 static int64_t coroutine_fn GRAPH_RDLOCK
-- 
2.34.1

Re: [PATCH v3 01/21] parallels: Set s->used_bmap to NULL in parallels_free_used_bitmap()

Posted by Denis V. Lunev 2 years, 1 month ago

On 10/27/23 09:46, Alexander Ivanov wrote:
> After used bitmap freeng s->used_bmap points to the freed memory. If we try
> to free used bitmap one more time it leads to double free error.
>
> Set s->used_bmap to NULL to exclude double free error.
>
> Signed-off-by: Alexander Ivanov <alexander.ivanov@virtuozzo.com>
> ---
>   block/parallels.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/block/parallels.c b/block/parallels.c
> index 1d695ce7fb..01a61a4ebd 100644
> --- a/block/parallels.c
> +++ b/block/parallels.c
> @@ -245,6 +245,7 @@ static void parallels_free_used_bitmap(BlockDriverState *bs)
>       BDRVParallelsState *s = bs->opaque;
>       s->used_bmap_size = 0;
>       g_free(s->used_bmap);
> +    s->used_bmap = NULL;
>   }
>   
>   static int64_t coroutine_fn GRAPH_RDLOCK
Reviewed-by: Denis V. Lunev <den@openvz.org>