[dm-devel] [PATCH 6/6] multipathd: return NULL if MALLOC fails in alloc_waiteri, func

[Martin Wilck]

On Sun, 2020-08-16 at 09:46 +0800, Zhiqiang Liu wrote:
> In alloc_waiter func, if MALLOC fails, wp is equal to NULL.
> If now we call memset(wp), segmentation fault will occur.
> 
> Signed-off-by: Zhiqiang Liu <liuzhiqiang26 at huawei.com>
> Signed-off-by: lixiaokeng <lixiaokeng at huawei.com>
> ---
>  multipathd/waiter.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/multipathd/waiter.c b/multipathd/waiter.c
> index e645766..80e6e6e 100644
> --- a/multipathd/waiter.c
> +++ b/multipathd/waiter.c
> @@ -33,8 +33,10 @@ static struct event_thread *alloc_waiter (void)
>  	struct event_thread *wp;
> 
>  	wp = (struct event_thread *)MALLOC(sizeof(struct
> event_thread));
> -	memset(wp, 0, sizeof(struct event_thread));
> +	if (!wp)
> +		return NULL;
> 
> +	memset(wp, 0, sizeof(struct event_thread));
>  	return wp;
>  }
> 

This is correct, but while you're at it, please also remove the
superfluous memset() call (counterintuitively, MALLOC(x) maps to
calloc(1, x)).

Martin