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From: Mimi Zohar <zohar@linux.vnet.ibm.com>
To: David Howells <dhowells@redhat.com>
Cc: Matthew Garrett <mjg59@google.com>,
	Mimi Zohar <zohar@linux.vnet.ibm.com>,
	linux-integrity@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	Eric Biederman <ebiederm@xmission.com>,
	kexec@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/3] kexec: call LSM hook for kexec_load syscall
Date: Thu, 12 Apr 2018 18:41:50 -0400	[thread overview]
Message-ID: <1523572911-16363-3-git-send-email-zohar@linux.vnet.ibm.com> (raw)
In-Reply-To: <1523572911-16363-1-git-send-email-zohar@linux.vnet.ibm.com>

Allow LSMs and IMA to differentiate between the kexec_load and
kexec_file_load syscalls by adding an "unnecessary" call to
security_kernel_read_file() in kexec_load.  This would be similar to the
existing init_module syscall calling security_kernel_read_file().

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
---
 kernel/kexec.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/kernel/kexec.c b/kernel/kexec.c
index aed8fb2564b3..d1386cfc6796 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_file(NULL, 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:[~2018-04-12 22:42 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-04-12 22:41 [PATCH 0/3] kexec: limit " Mimi Zohar
2018-04-12 22:41 ` [PATCH 1/3] ima: based on the "secure_boot" policy limit syscalls Mimi Zohar
2018-04-12 22:41 ` Mimi Zohar [this message]
2018-05-02 14:45   ` [PATCH 2/3] kexec: call LSM hook for kexec_load syscall Eric W. Biederman
2018-05-02 15:45     ` Mimi Zohar
2018-05-03 15:51       ` Eric W. Biederman
2018-05-03 16:05         ` Casey Schaufler
2018-05-03 16:42           ` Eric W. Biederman
2018-05-03 21:06             ` Mimi Zohar
2018-05-03 21:36               ` Eric W. Biederman
2018-04-12 22:41 ` [PATCH 3/3] ima: based on policy require signed kexec kernel images Mimi Zohar
2018-05-03 20:13 ` [PATCH 0/3] kexec: limit kexec_load syscall Eric W. Biederman
2018-05-03 20:39   ` Matthew Garrett
2018-05-03 21:58     ` Eric W. Biederman
2018-05-03 22:51       ` Matthew Garrett
2018-05-03 21:31   ` Mimi Zohar
2018-05-03 21:38     ` Eric W. Biederman
2018-05-03 21:57       ` Mimi Zohar
2018-05-03 23:03         ` Eric W. Biederman
2018-05-04  2:29           ` Mimi Zohar
2018-05-11  1:36 Mimi Zohar
2018-05-11  1:36 ` [PATCH 2/3] kexec: call LSM hook for " Mimi Zohar

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