Re: [PATCH] netlink: Don't shift on 64 for ngroups

[David Miller]

From: Dmitry Safonov <dima@xxxxxxxxxx>
Date: Sun,  5 Aug 2018 00:55:44 +0100

> @@ -1011,8 +1011,8 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
>  
>  	if (nlk->ngroups == 0)
>  		groups = 0;
> -	else
> -		groups &= (1ULL << nlk->ngroups) - 1;
> +	else if (nlk->ngroups < sizeof(long unsigned int))
> +		groups &= (1UL << nlk->ngroups) - 1;

Sizeof is in bytes, you want to compare against bits.