Re: [PATCH 3/3] capabilities: add cap userns sysctl mask

Jonathan Calmels <[email protected]> Mon, 20 May 2024 12:25:27 -0700
Newsgroups dev.linux.lists.containers,org.kernel.vger.keyrings,org.kernel.vger.linux-fsdevel,org.kernel.vger.linux-kernel,org.kernel.vger.linux-security-module
Message-ID <ptixqmplbovxmqy3obybwphsie2xaybfj46xyafdnol7bme4z4@4kwdljmrkdpn>
On Mon, May 20, 2024 at 07:30:14AM GMT, Tycho Andersen wrote:
> there is an ongoing effort (started at [0]) to constify the first arg
> here, since you're not supposed to write to it. Your usage looks
> correct to me, so I think all it needs is a literal "const" here.

Will do, along with the suggestions from Jarkko

> > +	struct ctl_table t;
> > +	unsigned long mask_array[2];
> > +	kernel_cap_t new_mask, *mask;
> > +	int err;
> > +
> > +	if (write && (!capable(CAP_SETPCAP) ||
> > +		      !capable(CAP_SYS_ADMIN)))
> > +		return -EPERM;
> 
> ...why CAP_SYS_ADMIN? You mention it in the changelog, but don't
> explain why.

No reason really, I was hoping we could decide what we want here.
UMH uses CAP_SYS_MODULE, Serge mentioned adding a new cap maybe.