Re: [PATCH v1] migration: fix RAMBlock add NULL check

[Fabiano Rosas <farosas@suse.de>]

Dmitry Frolov <frolov@swemel.ru> writes:

> qemu_ram_block_from_host() may return NULL, which will be dereferenced w/o
> check. Usualy return value is checked for this function.
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: c7c0e72408df5e7821c0e995122fb2fe0ac001f1 ("migration/ram: Handle RAM block resizes during precopy")
> Signed-off-by: Dmitry Frolov <frolov@swemel.ru>
> ---
>  migration/ram.c | 5 +++++
>  1 file changed, 5 insertions(+)
>
> diff --git a/migration/ram.c b/migration/ram.c
> index e4bfd39f08..bd4b7574e1 100644
> --- a/migration/ram.c
> +++ b/migration/ram.c
> @@ -4281,6 +4281,11 @@ static void ram_mig_ram_block_resized(RAMBlockNotifier *n, void *host,
>      RAMBlock *rb = qemu_ram_block_from_host(host, false, &offset);
>      Error *err = NULL;
>  
> +    if (!rb) {
> +        error_report("RAM block not found");
> +        return;
> +    }
> +
>      if (migrate_ram_is_ignored(rb)) {
>          return;
>      }

Reviewed-by: Fabiano Rosas <farosas@suse.de>