From:   Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
To:     Paul Moore <paul@paul-moore.com>,
        Roberto Sassu <roberto.sassu@huawei.com>,
        linux-kernel@vger.kernel.org
Cc:     Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Mimi Zohar <zohar@linux.ibm.com>,
        =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <linux@weissschuh.net>,
        Casey Schaufler <casey@schaufler-ca.com>,
        =?UTF-8?q?Christian=20G=C3=B6ttsche?= <cgzones@googlemail.com>,
        =?UTF-8?q?Micka=C3=ABl=20Sala=C3=BCn?= <mic@digikod.net>,
        Frederick Lawler <fred@cloudflare.com>
Subject: [PATCH v1 1/2] LSM: add a release() hook for the clean exit cleanup of the LSM modules
Date:   Sat, 11 Mar 2023 00:11:08 +0100
Message-Id: <20230310231107.10954-1-mirsad.todorovac@alu.unizg.hr>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The LSM modules, namely integrity, do not have a clean way to deallocate
resources allocated in the init() hook or later in their lifetime. The
resources are destroyed on kernel shutdown in an undefined order.

This will allow a .release member per LSM module and calling proper
destructors in a well-behaved order.

Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Thomas Weißschuh <linux@weissschuh.net>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Christian Göttsche <cgzones@googlemail.com>
Cc: Mickaël Salaün <mic@digikod.net>
Cc: Frederick Lawler <fred@cloudflare.com>

---
 include/linux/lsm_hooks.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 6e156d2acffc..d5a6ab9b5eb2 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1724,6 +1724,7 @@ struct lsm_info {
 	unsigned long flags;	/* Optional: flags describing LSM */
 	int *enabled;		/* Optional: controlled by CONFIG_LSM */
 	int (*init)(void);	/* Required. */
+	int (*release)(void);	/* Release associated resources */
 	struct lsm_blob_sizes *blobs; /* Optional: for blob sharing. */
 };
 

--
Mirsad Goran Todorovac
Sistem inženjer
Grafički fakultet | Akademija likovnih umjetnosti
Sveučilište u Zagrebu
 
System engineer
Faculty of Graphic Arts | Academy of Fine Arts
University of Zagreb, Republic of Croatia
The European Union

---
 include/linux/lsm_hooks.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 0a5ba81f7367..db3e57e7738b 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1724,6 +1724,7 @@ struct lsm_info {
 	unsigned long flags;	/* Optional: flags describing LSM */
 	int *enabled;		/* Optional: controlled by CONFIG_LSM */
 	int (*init)(void);	/* Required. */
+	int (*release)(void);	/* Release associated resources */
 	struct lsm_blob_sizes *blobs; /* Optional: for blob sharing. */
 };
 
-- 
2.30.2