From: Jiri Bohac <jbohac@suse.cz>
Date: Mon, 18 Feb 2019 12:44:58 +0000 (+0000)
Subject: kexec_file: Restrict at runtime if the kernel is locked down
X-Git-Tag: archive/raspbian/5.2.17-1+rpi1^2~52
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=ed3ce1b0527bc2506469e60df38404c7ed8c522e;p=linux.git

kexec_file: Restrict at runtime if the kernel is locked down

When KEXEC_SIG is not enabled, kernel should not load images through
kexec_file systemcall if the kernel is locked down unless IMA can be used
to validate the image.

[Modified by David Howells to fit with modifications to the previous patch
 and to return -EPERM if the kernel is locked down for consistency with
 other lockdowns]

Signed-off-by: Jiri Bohac <jbohac@suse.cz>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jiri Bohac <jbohac@suse.cz>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
cc: Chun-Yi Lee <jlee@suse.com>
cc: kexec@lists.infradead.org

Gbp-Pq: Topic features/all/lockdown
Gbp-Pq: Name 0009-kexec_file-Restrict-at-runtime-if-the-kernel-is-lock.patch
---

diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 0a06e120829..aa2f8d42d46 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -237,6 +237,14 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
 		}
 
 		ret = 0;
+		if (is_ima_appraise_enabled())
+			break;
+
+		if (kernel_is_locked_down(reason)) {
+			ret = -EPERM;
+			goto out;
+		}
+
 		break;
 
 		/* All other errors are fatal, including nomem, unparseable