On 04/05/17 at 09:15pm, David Howells wrote: > From: Matthew Garrett <matthew.garr...@nebula.com> > > kexec permits the loading and execution of arbitrary code in ring 0, which > is something that lock-down is meant to prevent. It makes sense to disable > kexec in this situation. > > This does not affect kexec_file_load() which can check for a signature on the > image to be booted. > > Signed-off-by: Matthew Garrett <matthew.garr...@nebula.com> > Signed-off-by: David Howells <dhowe...@redhat.com> > cc: ke...@lists.infradead.org > --- > > kernel/kexec.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/kernel/kexec.c b/kernel/kexec.c > index 980936a90ee6..46de8e6b42f4 100644 > --- a/kernel/kexec.c > +++ b/kernel/kexec.c > @@ -194,6 +194,13 @@ SYSCALL_DEFINE4(kexec_load, unsigned long, entry, > unsigned long, nr_segments, > return -EPERM; > > /* > + * kexec can be used to circumvent module loading restrictions, so > + * prevent loading in that case > + */ > + if (kernel_is_locked_down()) > + return -EPERM; > + > + /* > * Verify we have a legal set of flags > * This leaves us room for future extensions. > */ > > > _______________________________________________ > kexec mailing list > ke...@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec
Acked-by: Dave Young <dyo...@redhat.com> Thanks Dave
