[PATCH 06/58] LSM: Use lsm_export in the cred_getsecid hooks

From: Casey Schaufler <casey@schaufler-ca.com>
To: casey.schaufler@intel.com, jmorris@namei.org,
	linux-security-module@vger.kernel.org, selinux@vger.kernel.org
Cc: casey@schaufler-ca.com, keescook@chromium.org,
	john.johansen@canonical.com, penguin-kernel@i-love.sakura.ne.jp,
	paul@paul-moore.com, sds@tycho.nsa.gov
Subject: [PATCH 06/58] LSM: Use lsm_export in the cred_getsecid hooks
Date: Fri, 31 May 2019 16:30:57 -0700	[thread overview]
Message-ID: <20190531233149.715-7-casey@schaufler-ca.com> (raw)
In-Reply-To: <20190531233149.715-1-casey@schaufler-ca.com>

Convert the cred_getsecid hooks to use the lsm_export
structure instead of a u32 secid. There is some scaffolding
involved that will be removed when security_cred_getsecid()
is updated.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hooks.h  | 5 +++--
 security/security.c        | 6 ++++--
 security/selinux/hooks.c   | 4 ++--
 security/smack/smack_lsm.c | 4 ++--
 4 files changed, 11 insertions(+), 8 deletions(-)

diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 09573c55e535..0f9d4174bb6e 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -572,7 +572,8 @@
  *	Transfer data from original creds to new creds
  * @cred_getsecid:
  *	Retrieve the security identifier of the cred structure @c
- *	@c contains the credentials, secid will be placed into @secid.
+ *	@c contains the credentials
+ *	@l contains a pointer to the location where result will be saved.
  *	In case of failure, @secid will be set to zero.
  * @kernel_act_as:
  *	Set the credentials for a kernel service to act as (subjective context).
@@ -1596,7 +1597,7 @@ union security_list_options {
 	int (*cred_prepare)(struct cred *new, const struct cred *old,
 				gfp_t gfp);
 	void (*cred_transfer)(struct cred *new, const struct cred *old);
-	void (*cred_getsecid)(const struct cred *c, u32 *secid);
+	void (*cred_getsecid)(const struct cred *c, struct lsm_export *l);
 	int (*kernel_act_as)(struct cred *new, u32 secid);
 	int (*kernel_create_files_as)(struct cred *new, struct inode *inode);
 	int (*kernel_module_request)(char *kmod_name);
diff --git a/security/security.c b/security/security.c
index a1f28a5e582b..ca485a777ca1 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1638,8 +1638,10 @@ void security_transfer_creds(struct cred *new, const struct cred *old)
 
 void security_cred_getsecid(const struct cred *c, u32 *secid)
 {
-	*secid = 0;
-	call_void_hook(cred_getsecid, c, secid);
+	struct lsm_export data = { .flags = LSM_EXPORT_NONE };
+
+	call_void_hook(cred_getsecid, c, &data);
+	lsm_export_secid(&data, secid);
 }
 EXPORT_SYMBOL(security_cred_getsecid);
 
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 0e31be22d9bb..f97dd414ac8d 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3764,9 +3764,9 @@ static void selinux_cred_transfer(struct cred *new, const struct cred *old)
 	*tsec = *old_tsec;
 }
 
-static void selinux_cred_getsecid(const struct cred *c, u32 *secid)
+static void selinux_cred_getsecid(const struct cred *c, struct lsm_export *l)
 {
-	*secid = cred_sid(c);
+	selinux_export_secid(l, cred_sid(c));
 }
 
 /*
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 5e345122ccb1..15579bdd7244 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1980,13 +1980,13 @@ static void smack_cred_transfer(struct cred *new, const struct cred *old)
  *
  * Sets the secid to contain a u32 version of the smack label.
  */
-static void smack_cred_getsecid(const struct cred *cred, u32 *secid)
+static void smack_cred_getsecid(const struct cred *cred, struct lsm_export *l)
 {
 	struct smack_known *skp;
 
 	rcu_read_lock();
 	skp = smk_of_task(smack_cred(cred));
-	*secid = skp->smk_secid;
+	smack_export_secid(l, skp->smk_secid);
 	rcu_read_unlock();
 }
 
-- 
2.19.1

