[PATCH v4 05/13] LSM: Use lsm_prop in security_ipc_getsecid

Casey Schaufler casey at schaufler-ca.com
Wed Oct 9 17:32:13 UTC 2024


There may be more than one LSM that provides IPC data for auditing.
Change security_ipc_getsecid() to fill in a lsm_prop structure instead
of the u32 secid.  Change the name to security_ipc_getlsmprop() to
reflect the change.

Signed-off-by: Casey Schaufler <casey at schaufler-ca.com>
Cc: audit at vger.kernel.org
Cc: linux-security-module at vger.kernel.org
Cc: selinux at vger.kernel.org
---
 include/linux/lsm_hook_defs.h |  4 ++--
 include/linux/security.h      | 22 +++++++++++++++++-----
 kernel/auditsc.c              |  5 ++---
 security/security.c           | 14 +++++++-------
 security/selinux/hooks.c      |  9 ++++++---
 security/smack/smack_lsm.c    | 16 +++++++++-------
 6 files changed, 43 insertions(+), 27 deletions(-)

diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index ed6ea0b1ec57..6ef2a345ea03 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -256,8 +256,8 @@ LSM_HOOK(void, LSM_RET_VOID, task_to_inode, struct task_struct *p,
 	 struct inode *inode)
 LSM_HOOK(int, 0, userns_create, const struct cred *cred)
 LSM_HOOK(int, 0, ipc_permission, struct kern_ipc_perm *ipcp, short flag)
-LSM_HOOK(void, LSM_RET_VOID, ipc_getsecid, struct kern_ipc_perm *ipcp,
-	 u32 *secid)
+LSM_HOOK(void, LSM_RET_VOID, ipc_getlsmprop, struct kern_ipc_perm *ipcp,
+	 struct lsm_prop *prop)
 LSM_HOOK(int, 0, msg_msg_alloc_security, struct msg_msg *msg)
 LSM_HOOK(void, LSM_RET_VOID, msg_msg_free_security, struct msg_msg *msg)
 LSM_HOOK(int, 0, msg_queue_alloc_security, struct kern_ipc_perm *perm)
diff --git a/include/linux/security.h b/include/linux/security.h
index 5652baa4ca3c..15aef5f68e77 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -289,6 +289,17 @@ static inline const char *kernel_load_data_id_str(enum kernel_load_data_id id)
 	return kernel_load_data_str[id];
 }
 
+/**
+ * lsmprop_init - initialize a lsm_prop structure
+ * @prop: Pointer to the data to initialize
+ *
+ * Set all secid for all modules to the specified value.
+ */
+static inline void lsmprop_init(struct lsm_prop *prop)
+{
+	memset(prop, 0, sizeof(*prop));
+}
+
 #ifdef CONFIG_SECURITY
 
 /**
@@ -297,7 +308,7 @@ static inline const char *kernel_load_data_id_str(enum kernel_load_data_id id)
  *
  * Returns true if there is a value set, false otherwise
  */
-static inline bool lsm_prop_is_set(struct lsm_prop *prop)
+static inline bool lsmprop_is_set(struct lsm_prop *prop)
 {
 	const struct lsm_prop empty = {};
 
@@ -515,7 +526,7 @@ int security_task_prctl(int option, unsigned long arg2, unsigned long arg3,
 void security_task_to_inode(struct task_struct *p, struct inode *inode);
 int security_create_user_ns(const struct cred *cred);
 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_getlsmprop(struct kern_ipc_perm *ipcp, struct lsm_prop *prop);
 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);
@@ -571,7 +582,7 @@ int security_bdev_setintegrity(struct block_device *bdev,
  *
  * Returns true if there is a value set, false otherwise
  */
-static inline bool lsm_prop_is_set(struct lsm_prop *prop)
+static inline bool lsmprop_is_set(struct lsm_prop *prop)
 {
 	return false;
 }
@@ -1377,9 +1388,10 @@ 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_getlsmprop(struct kern_ipc_perm *ipcp,
+					   struct lsm_prop *prop)
 {
-	*secid = 0;
+	lsmprop_init(prop);
 }
 
 static inline int security_msg_msg_alloc(struct msg_msg *msg)
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index e89499819817..5019eb32a97f 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -1397,7 +1397,7 @@ static void show_special(struct audit_context *context, int *call_panic)
 				 from_kuid(&init_user_ns, context->ipc.uid),
 				 from_kgid(&init_user_ns, context->ipc.gid),
 				 context->ipc.mode);
-		if (lsm_prop_is_set(&context->ipc.oprop)) {
+		if (lsmprop_is_set(&context->ipc.oprop)) {
 			char *ctx = NULL;
 			u32 len;
 
@@ -2638,8 +2638,7 @@ void __audit_ipc_obj(struct kern_ipc_perm *ipcp)
 	context->ipc.gid = ipcp->gid;
 	context->ipc.mode = ipcp->mode;
 	context->ipc.has_perm = 0;
-	/* scaffolding */
-	security_ipc_getsecid(ipcp, &context->ipc.oprop.scaffold.secid);
+	security_ipc_getlsmprop(ipcp, &context->ipc.oprop);
 	context->type = AUDIT_IPC;
 }
 
diff --git a/security/security.c b/security/security.c
index 1842f1325e77..f269421c2d72 100644
--- a/security/security.c
+++ b/security/security.c
@@ -3730,17 +3730,17 @@ int security_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
 }
 
 /**
- * security_ipc_getsecid() - Get the sysv ipc object's secid
+ * security_ipc_getlsmprop() - Get the sysv ipc object LSM data
  * @ipcp: ipc permission structure
- * @secid: secid pointer
+ * @prop: pointer to lsm information
  *
- * Get the secid associated with the ipc object.  In case of failure, @secid
- * will be set to zero.
+ * Get the lsm information associated with the ipc object.
  */
-void security_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+
+void security_ipc_getlsmprop(struct kern_ipc_perm *ipcp, struct lsm_prop *prop)
 {
-	*secid = 0;
-	call_void_hook(ipc_getsecid, ipcp, secid);
+	lsmprop_init(prop);
+	call_void_hook(ipc_getlsmprop, ipcp, prop);
 }
 
 /**
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 6e88faf3c6e5..1d43367009ed 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -6319,10 +6319,13 @@ static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
 	return ipc_has_perm(ipcp, av);
 }
 
-static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
+static void selinux_ipc_getlsmprop(struct kern_ipc_perm *ipcp,
+				   struct lsm_prop *prop)
 {
 	struct ipc_security_struct *isec = selinux_ipc(ipcp);
-	*secid = isec->sid;
+	prop->selinux.secid = isec->sid;
+	/* scaffolding */
+	prop->scaffold.secid = isec->sid;
 }
 
 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
@@ -7215,7 +7218,7 @@ static struct security_hook_list selinux_hooks[] __ro_after_init = {
 	LSM_HOOK_INIT(userns_create, selinux_userns_create),
 
 	LSM_HOOK_INIT(ipc_permission, selinux_ipc_permission),
-	LSM_HOOK_INIT(ipc_getsecid, selinux_ipc_getsecid),
+	LSM_HOOK_INIT(ipc_getlsmprop, selinux_ipc_getlsmprop),
 
 	LSM_HOOK_INIT(msg_queue_associate, selinux_msg_queue_associate),
 	LSM_HOOK_INIT(msg_queue_msgctl, selinux_msg_queue_msgctl),
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 66da7cbcc0b7..fed44b4fc73d 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3435,16 +3435,18 @@ static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
 }
 
 /**
- * smack_ipc_getsecid - Extract smack security id
+ * smack_ipc_getlsmprop - Extract smack security data
  * @ipp: the object permissions
- * @secid: where result will be saved
+ * @prop: where result will be saved
  */
-static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
+static void smack_ipc_getlsmprop(struct kern_ipc_perm *ipp, struct lsm_prop *prop)
 {
-	struct smack_known **blob = smack_ipc(ipp);
-	struct smack_known *iskp = *blob;
+	struct smack_known **iskpp = smack_ipc(ipp);
+	struct smack_known *iskp = *iskpp;
 
-	*secid = iskp->smk_secid;
+	prop->smack.skp = iskp;
+	/* scaffolding */
+	prop->scaffold.secid = iskp->smk_secid;
 }
 
 /**
@@ -5140,7 +5142,7 @@ static struct security_hook_list smack_hooks[] __ro_after_init = {
 	LSM_HOOK_INIT(task_to_inode, smack_task_to_inode),
 
 	LSM_HOOK_INIT(ipc_permission, smack_ipc_permission),
-	LSM_HOOK_INIT(ipc_getsecid, smack_ipc_getsecid),
+	LSM_HOOK_INIT(ipc_getlsmprop, smack_ipc_getlsmprop),
 
 	LSM_HOOK_INIT(msg_msg_alloc_security, smack_msg_msg_alloc_security),
 
-- 
2.46.0




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