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Date:   Wed, 11 Mar 2020 11:08:05 -0700
From:   Eric Biggers <ebiggers@kernel.org>
To:     Luis Chamberlain <mcgrof@kernel.org>
Cc:     Kees Cook <keescook@chromium.org>, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org, stable@vger.kernel.org,
        Alexei Starovoitov <ast@kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Jeff Vander Stoep <jeffv@google.com>,
        Jessica Yu <jeyu@kernel.org>
Subject: Re: [PATCH] kmod: make request_module() return an error when
 autoloading is disabled
Message-ID: <20200311180805.GA1273@sol.localdomain>
References: <20200310223731.126894-1-ebiggers@kernel.org>
 <202003111026.2BBE41C@keescook>
 <20200311174134.GB20006@gmail.com>
 <20200311180107.GO11244@42.do-not-panic.com>
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On Wed, Mar 11, 2020 at 06:01:07PM +0000, Luis Chamberlain wrote:
> On Wed, Mar 11, 2020 at 10:41:34AM -0700, Eric Biggers wrote:
> > On Wed, Mar 11, 2020 at 10:28:07AM -0700, Kees Cook wrote:
> > > On Tue, Mar 10, 2020 at 03:37:31PM -0700, Eric Biggers wrote:
> > > > From: Eric Biggers <ebiggers@google.com>
> > > > 
> > > > It's long been possible to disable kernel module autoloading completely
> > > > by setting /proc/sys/kernel/modprobe to the empty string.  This can be
> > > 
> > > Hunh. I've never seen that before. :) I've always used;
> > > 
> > > echo 1 > /proc/sys/kernel/modules_disabled
> > > 
> > > Regardless,
> > > 
> > > Reviewed-by: Kees Cook <keescook@chromium.org>
> > > 
> > 
> > modules_disabled is different because it disables *all* module loading, not just
> > autoloading.
> 
> Clarifying this on your patch would be useful, otherwise its lost
> tribal knowledge.

I think it would be more useful to improve the documentation in proc(5) and
Documentation/admin-guide/sysctl/kernel.rst.  People shouldn't have to read
random kernel commit messages to find the documentation.

I'll send out patches for those.

- Eric