[PATCH v2 5/6] LSM: Infrastructure management of the infiniband blob

[Casey Schaufler <casey@schaufler-ca.com>]

Move management of the infiniband security blob out of the individual
security modules and into the LSM infrastructure.  The security modules
tell the infrastructure how much space they require at initialization.
There are no longer any modules that require the ib_free() hook.
The hook definition has been removed.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
---
 include/linux/lsm_hook_defs.h     |  3 +--
 include/linux/lsm_hooks.h         |  1 +
 security/security.c               | 17 +++++++++++++++--
 security/selinux/hooks.c          | 16 +++-------------
 security/selinux/include/objsec.h |  6 ++++++
 5 files changed, 26 insertions(+), 17 deletions(-)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index f1e0d6138845..7c979137c0f2 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -372,8 +372,7 @@ LSM_HOOK(int, 0, mptcp_add_subflow, struct sock *sk, struct sock *ssk)
 LSM_HOOK(int, 0, ib_pkey_access, void *sec, u64 subnet_prefix, u16 pkey)
 LSM_HOOK(int, 0, ib_endport_manage_subnet, void *sec, const char *dev_name,
 	 u8 port_num)
-LSM_HOOK(int, 0, ib_alloc_security, void **sec)
-LSM_HOOK(void, LSM_RET_VOID, ib_free_security, void *sec)
+LSM_HOOK(int, 0, ib_alloc_security, void *sec)
 #endif /* CONFIG_SECURITY_INFINIBAND */
 
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 0ff14ff128c8..b6fc6ac88723 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -72,6 +72,7 @@ struct security_hook_list {
 struct lsm_blob_sizes {
 	int	lbs_cred;
 	int	lbs_file;
+	int	lbs_ib;
 	int	lbs_inode;
 	int	lbs_sock;
 	int	lbs_superblock;
diff --git a/security/security.c b/security/security.c
index f1eb93b65ae9..e8f34cbb1990 100644
--- a/security/security.c
+++ b/security/security.c
@@ -219,6 +219,7 @@ static void __init lsm_set_blob_sizes(struct lsm_blob_sizes *needed)
 
 	lsm_set_blob_size(&needed->lbs_cred, &blob_sizes.lbs_cred);
 	lsm_set_blob_size(&needed->lbs_file, &blob_sizes.lbs_file);
+	lsm_set_blob_size(&needed->lbs_ib, &blob_sizes.lbs_ib);
 	/*
 	 * The inode blob gets an rcu_head in addition to
 	 * what the modules might need.
@@ -402,6 +403,7 @@ static void __init ordered_lsm_init(void)
 
 	init_debug("cred blob size       = %d\n", blob_sizes.lbs_cred);
 	init_debug("file blob size       = %d\n", blob_sizes.lbs_file);
+	init_debug("ib blob size         = %d\n", blob_sizes.lbs_ib);
 	init_debug("inode blob size      = %d\n", blob_sizes.lbs_inode);
 	init_debug("ipc blob size        = %d\n", blob_sizes.lbs_ipc);
 #ifdef CONFIG_KEYS
@@ -5070,7 +5072,18 @@ EXPORT_SYMBOL(security_ib_endport_manage_subnet);
  */
 int security_ib_alloc_security(void **sec)
 {
-	return call_int_hook(ib_alloc_security, sec);
+	int rc;
+
+	rc = lsm_blob_alloc(sec, blob_sizes.lbs_ib, GFP_KERNEL);
+	if (rc)
+		return rc;
+
+	rc = call_int_hook(ib_alloc_security, *sec);
+	if (rc) {
+		kfree(*sec);
+		*sec = NULL;
+	}
+	return rc;
 }
 EXPORT_SYMBOL(security_ib_alloc_security);
 
@@ -5082,7 +5095,7 @@ EXPORT_SYMBOL(security_ib_alloc_security);
  */
 void security_ib_free_security(void *sec)
 {
-	call_void_hook(ib_free_security, sec);
+	kfree(sec);
 }
 EXPORT_SYMBOL(security_ib_free_security);
 #endif	/* CONFIG_SECURITY_INFINIBAND */
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 34ed787a4bfa..11f4bdabda97 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6776,23 +6776,13 @@ static int selinux_ib_endport_manage_subnet(void *ib_sec, const char *dev_name,
 			    INFINIBAND_ENDPORT__MANAGE_SUBNET, &ad);
 }
 
-static int selinux_ib_alloc_security(void **ib_sec)
+static int selinux_ib_alloc_security(void *ib_sec)
 {
-	struct ib_security_struct *sec;
+	struct ib_security_struct *sec = selinux_ib(ib_sec);
 
-	sec = kzalloc(sizeof(*sec), GFP_KERNEL);
-	if (!sec)
-		return -ENOMEM;
 	sec->sid = current_sid();
-
-	*ib_sec = sec;
 	return 0;
 }
-
-static void selinux_ib_free_security(void *ib_sec)
-{
-	kfree(ib_sec);
-}
 #endif
 
 #ifdef CONFIG_BPF_SYSCALL
@@ -6964,6 +6954,7 @@ struct lsm_blob_sizes selinux_blob_sizes __ro_after_init = {
 	.lbs_superblock = sizeof(struct superblock_security_struct),
 	.lbs_xattr_count = SELINUX_INODE_INIT_XATTRS,
 	.lbs_tun_dev = sizeof(struct tun_security_struct),
+	.lbs_ib = sizeof(struct ib_security_struct),
 };
 
 #ifdef CONFIG_PERF_EVENTS
@@ -7282,7 +7273,6 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = {
 	LSM_HOOK_INIT(ib_pkey_access, selinux_ib_pkey_access),
 	LSM_HOOK_INIT(ib_endport_manage_subnet,
 		      selinux_ib_endport_manage_subnet),
-	LSM_HOOK_INIT(ib_free_security, selinux_ib_free_security),
 #endif
 #ifdef CONFIG_SECURITY_NETWORK_XFRM
 	LSM_HOOK_INIT(xfrm_policy_free_security, selinux_xfrm_policy_free),
diff --git a/security/selinux/include/objsec.h b/security/selinux/include/objsec.h
index 461c6985977d..b1878f9395b5 100644
--- a/security/selinux/include/objsec.h
+++ b/security/selinux/include/objsec.h
@@ -213,4 +213,10 @@ selinux_tun_dev(void *security)
 	return security + selinux_blob_sizes.lbs_tun_dev;
 }
 
+static inline struct ib_security_struct *
+selinux_ib(void *ib_sec)
+{
+	return ib_sec + selinux_blob_sizes.lbs_ib;
+}
+
 #endif /* _SELINUX_OBJSEC_H_ */
-- 
2.45.2