[PATCH V3 08/11] nvmet: use min of device_path and disk len

[Christoph Hellwig]

>  static inline void __assign_req_name(char *name, struct nvmet_req *req)
>  {
> +	size_t len = min_t(size_t, DISK_NAME_LEN, strlen(req->ns->device_path));
> +
>  	if (req->ns)
> -		strncpy(name, req->ns->device_path, DISK_NAME_LEN);
> +		strncpy(name, req->ns->device_path, len);
>  	else
>  		memset(name, 0, DISK_NAME_LEN);

This could dereference a NULL req->ns.  I've changed the patch
to eliminate the local variable and to return early for the NULL
req->ns case.