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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180804.170856.2031275734761112973.davem@davemloft.net>
Date:   Sat, 04 Aug 2018 17:08:56 -0700 (PDT)
From:   David Miller <davem@...emloft.net>
To:     dima@...sta.com
Cc:     linux-kernel@...r.kernel.org, natechancellor@...il.com,
        herbert@...dor.apana.org.au, steffen.klassert@...unet.com,
        netdev@...r.kernel.org, stable@...r.kernel.org
Subject: Re: [PATCH] netlink: Don't shift on 64 for ngroups

From: Dmitry Safonov <dima@...sta.com>
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.