Thread (41 messages) 41 messages, 7 authors, 2018-06-06
STALE2919d
Revisions (5)
  1. v2 [diff vs current]
  2. v3 [diff vs current]
  3. v4 current
  4. v5 [diff vs current]
  5. v6 [diff vs current]

[PATCH v4 2/8] kexec: add call to LSM hook in original kexec_load syscall

From: Mimi Zohar <hidden>
Date: 2018-05-29 18:02:32
Also in: kexec, linux-integrity, lkml
Subsystem: kexec, the rest · Maintainers: Andrew Morton, Baoquan He, Mike Rapoport, Pasha Tatashin, Pratyush Yadav, Linus Torvalds

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 <redacted>
Cc: Eric Biederman <redacted>
Cc: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <redacted>
Cc: David Howells <dhowells@redhat.com>
---
 kernel/kexec.c | 8 ++++++++
 1 file changed, 8 insertions(+)
diff --git a/kernel/kexec.c b/kernel/kexec.c
index aed8fb2564b3..68559808fdfa 100644
--- 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.
-- 
2.7.5

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