Re: [PATCH] kernel/groups.c: consider about NULL for 'group_info' in all related extern functions

Tejun Heo
2013-09-24T12:04:37Z

On Tue, Sep 24, 2013 at 12:27:36PM +0800, Chen Gang wrote:
> For real world, /sbin/init will call setgroups, so user space 'help'
> kernel itself to protect this issue, but I think, we don't only depend
> on the user space help checking.
>
> The proof is below:
>
> [root@gchenlinux tmp]# grep setgroups /sbin/*
> Binary file /sbin/init matches
> Binary file /sbin/rpc.statd matches
> Binary file /sbin/rsyslogd matches
> Binary file /sbin/runuser matches
>
> From reading kernel source code, kernel itself does not intend to set
> 'group_info', it is triggered by user space or another kernel mode
> sub-systems.

Can you please demonstrate such failure? You can tell kernel to
execute a given binary instead of init with "init=" param.

Thanks.

--
tejun