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 <[email protected]> Cc: Eric Biederman <[email protected]> Cc: Kees Cook <[email protected]> Acked-by: Serge Hallyn <[email protected]> Acked-by: Kees Cook <[email protected]> Signed-off-by: James Morris <[email protected]>
chewitt · Jul 16, 2018 · a210fd3 · a210fd3
1 parent 377179c
commit a210fd3
Showing 1 changed file with 8 additions and 0 deletions.
diff --git 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 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
 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.