[PATCH v2 10/25] LSM: Use lsmblob in security_ipc_getsecid

[Casey Schaufler]

There may be more than one LSM that provides IPC data
for auditing. Change security_ipc_getsecid() to fill in
a lsmblob structure instead of the u32 secid. The
audit data structure containing the secid will be updated
later, so there is a bit of scaffolding here.

Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
---
 include/linux/security.h | 7 ++++---
 kernel/auditsc.c         | 5 ++++-
 security/security.c      | 9 ++++++---
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/include/linux/security.h b/include/linux/security.h
index c9ed83e57a97..ae448814f169 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -413,7 +413,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
 			unsigned long arg4, unsigned long arg5);
 void security_task_to_inode(struct task_struct *p, struct inode *inode);
 int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag);
-void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid);
+void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *l);
 int security_msg_msg_alloc(struct msg_msg *msg);
 void security_msg_msg_free(struct msg_msg *msg);
 int security_msg_queue_alloc(struct kern_ipc_perm *msq);
@@ -1098,9 +1098,10 @@ static inline int security_ipc_permission(struct kern_ipc_perm *ipcp,
 	return 0;
 }
 
-static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+static inline void security_ipc_getsecid(struct kern_ipc_perm *ipcp,
+					 struct lsmblob *l)
 {
-	*secid = 0;
+	lsmblob_init(l, 0);
 }
 
 static inline int security_msg_msg_alloc(struct msg_msg *msg)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 67d3f71a095a..a094f58aebbc 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -2266,11 +2266,14 @@ void __audit_mq_getsetattr(mqd_t mqdes, struct mq_attr *mqstat)
 void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
 {
 	struct audit_context *context = audit_context();
+	struct lsmblob le;
 	context->ipc.uid = ipcp->uid;
 	context->ipc.gid = ipcp->gid;
 	context->ipc.mode = ipcp->mode;
 	context->ipc.has_perm = 0;
-	security_ipc_getsecid(ipcp, &context->ipc.osid);
+	security_ipc_getsecid(ipcp, &le);
+	/* scaffolding on the [1] - change "osid" to a lsmblob */
+	context->ipc.osid = le.secid[1];
 	context->type = AUDIT_IPC;
 }
 
diff --git a/security/security.c b/security/security.c
index 561a41eccbd9..bd929866ce0d 100644
--- a/security/security.c
+++ b/security/security.c
@@ -1807,10 +1807,13 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
 	return call_int_hook(ipc_permission, 0, ipcp, flag);
 }
 
-void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+void security_ipc_getsecid(struct kern_ipc_perm *ipcp, struct lsmblob *l)
 {
-	*secid = 0;
-	call_void_hook(ipc_getsecid, ipcp, secid);
+	struct security_hook_list *hp;
+
+	lsmblob_init(l, 0);
+	hlist_for_each_entry(hp, &security_hook_heads.ipc_getsecid, list)
+		hp->hook.ipc_getsecid(ipcp, &l->secid[hp->slot]);
 }
 
 int security_msg_msg_alloc(struct msg_msg *msg)
-- 
2.20.1