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From: Mimi Zohar <zohar@linux.vnet.ibm.com>
To: linux-integrity@vger.kernel.org
Cc: Mimi Zohar <zohar@linux.vnet.ibm.com>,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org, David Howells <dhowells@redhat.com>,
	"Luis R . Rodriguez" <mcgrof@kernel.org>,
	Eric Biederman <ebiederm@xmission.com>,
	kexec@lists.infradead.org, Andres Rodriguez <andresx7@gmail.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Kees Cook <keescook@chromium.org>
Subject: [PATCH v2 4/9] kexec: add call to LSM hook in original kexec_load syscall
Date: Thu, 17 May 2018 10:48:45 -0400	[thread overview]
Message-ID: <1526568530-9144-5-git-send-email-zohar@linux.vnet.ibm.com> (raw)
In-Reply-To: <1526568530-9144-1-git-send-email-zohar@linux.vnet.ibm.com>

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

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
---
 kernel/kexec.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index aed8fb2564b3..64cebe92a690 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>
@@ -195,11 +196,21 @@ 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;
 
 	/*
+	 * Allow LSMs and IMA to differentiate between kexec_load and
+	 * kexec_file_load syscalls.
+	 */
+	result = security_kernel_read_blob(READING_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

  parent reply	other threads:[~2018-05-17 14:48 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-05-17 14:48 [PATCH v2 0/9] kexec/firmware: support system wide policy requiring signatures Mimi Zohar
2018-05-17 14:48 ` [PATCH v2 1/9] ima: based on policy verify firmware signatures (pre-allocated buffer) Mimi Zohar
2018-05-17 14:48 ` [PATCH v2 2/9] ima: fix updating the ima_appraise flag Mimi Zohar
2018-05-17 14:48 ` [PATCH v2 3/9] security: define security_kernel_read_blob() wrapper Mimi Zohar
2018-05-18  0:24   ` Casey Schaufler
2018-05-18  3:37     ` Eric W. Biederman
2018-05-18 11:30       ` Mimi Zohar
2018-05-18 14:58         ` Casey Schaufler
2018-05-18 15:29           ` Mimi Zohar
2018-05-18 17:13       ` James Morris
2018-05-18 17:55         ` Mimi Zohar
2018-05-17 14:48 ` Mimi Zohar [this message]
2018-05-17 14:48 ` [PATCH v2 5/9] ima: based on policy require signed kexec kernel images Mimi Zohar
2018-05-17 14:48 ` [PATCH v2 6/9] firmware: add call to LSM hook before firmware sysfs fallback Mimi Zohar
2018-05-17 14:48 ` [PATCH v2 7/9] ima: based on policy require signed firmware (sysfs fallback) Mimi Zohar
2018-05-17 14:48 ` [PATCH v2 8/9] ima: add build time policy Mimi Zohar
2018-05-17 14:48 ` [PATCH v2 9/9] ima: based on policy prevent loading firmware (pre-allocated buffer) Mimi Zohar

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