Re: [PATCH v2] fs: warn in case userspace lied about modprobe return

From: Luis R. Rodriguez
Date: Fri Jun 23 2017 - 14:28:59 EST


On Tue, Jun 20, 2017 at 10:57:46PM +0200, Luis R. Rodriguez wrote:
> On Thu, Jun 01, 2017 at 11:08:01AM -0700, Luis R. Rodriguez wrote:
> > kmod <= v19 was broken -- it could return 0 to modprobe calls,
> > incorrectly assuming that a kernel module was built-in, whereas in
> > reality the module was just forming in the kernel. The reason for this
> > is an incorrect userspace heuristics. A userspace kmod fix is available
> > for it [0], however should userspace break again we could go on with
> > an failed get_fs_type() which is hard to debug as the request_module()
> > is detected as returning 0. The first suspect would be that there is
> > something worth with the kernel's module loader and obviously in this
> > case that is not the issue.
> >
> > Since these issues are painful to debug complain when we know userspace
> > has outright lied to us.
> >
> > [0] http://git.kernel.org/cgit/utils/kernel/kmod/kmod.git/commit/libkmod/libkmod-module.c?id=fd44a98ae2eb5eb32161088954ab21e58e19dfc4
> >
> > Suggested-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
> > Cc: Jessica Yu <jeyu@xxxxxxxxxx>
> > Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>
>
> *poke* Al?

Will bounce to the default tree maintainer, Andrew :)

Luis