From: Chun-Yi Lee <joeyli.ker...@gmail.com>

When KEXEC_VERIFY_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.

This code was showed in Matthew's patch but not in git:
https://lkml.org/lkml/2015/3/13/778

Cc: Matthew Garrett <mj...@srcf.ucam.org>
Signed-off-by: Chun-Yi Lee <j...@suse.com>
Signed-off-by: David Howells <dhowe...@redhat.com>
Reviewed-by: James Morris <james.l.mor...@oracle.com>
cc: ke...@lists.infradead.org
---

 kernel/kexec_file.c |    8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 9f48f4412297..3ba28fc3fab0 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -255,6 +255,14 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, 
initrd_fd,
        if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
                return -EPERM;
 
+       /* Don't permit images to be loaded into trusted kernels if we're not
+        * going to verify the signature on them
+        */
+       if (!IS_ENABLED(CONFIG_KEXEC_VERIFY_SIG) &&
+           !is_ima_appraise_enabled() &&
+           kernel_is_locked_down("kexec of unsigned images"))
+               return -EPERM;
+
        /* Make sure we have a legal set of flags */
        if (flags != (flags & KEXEC_FILE_FLAGS))
                return -EINVAL;

--
To unsubscribe from this list: send the line "unsubscribe linux-efi" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to