kexec: add call to LSM hook in original kexec_load syscall

In order for LSMs and IMA-appraisal to differentiate between kexec_load
and kexec_file_load syscalls, both the original and new syscalls must
call an LSM hook.  This patch adds a call to security_kernel_load_data()
in the original kexec_load syscall.

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>

diff --git a/kernel/kexec.c b/kernel/kexec.c
index aed8fb2..6855980 100644 (file)
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -11,6 +11,7 @@
 #include <linux/capability.h>
 #include <linux/mm.h>
 #include <linux/file.h>
+#include <linux/security.h>
 #include <linux/kexec.h>
 #include <linux/mutex.h>
 #include <linux/list.h>
@@ -195,10 +196,17 @@ out:
 static inline int kexec_load_check(unsigned long nr_segments,
                                   unsigned long flags)
 {
+       int result;
+
        /* We only trust the superuser with rebooting the system. */
        if (!capable(CAP_SYS_BOOT) || kexec_load_disabled)
                return -EPERM;
 
+       /* Permit LSMs and IMA to fail the kexec */
+       result = security_kernel_load_data(LOADING_KEXEC_IMAGE);
+       if (result < 0)
+               return result;
+
        /*
         * Verify we have a legal set of flags
         * This leaves us room for future extensions.