1 files changed, 77 insertions, 5 deletions
diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h
index 1931370233d7..e4e50bb218ee 100644
--- a/security/selinux/include/avc.h
+++ b/security/selinux/include/avc.h
@@ -77,11 +77,83 @@ struct selinux_audit_data {
 
 void __init avc_init(void);
 
-int avc_audit(u32 ssid, u32 tsid,
-	       u16 tclass, u32 requested,
-	       struct av_decision *avd,
-	       int result,
-	      struct common_audit_data *a, unsigned flags);
+static inline u32 avc_audit_required(u32 requested,
+			      struct av_decision *avd,
+			      int result,
+			      u32 auditdeny,
+			      u32 *deniedp)
+{
+	u32 denied, audited;
+	denied = requested & ~avd->allowed;
+	if (unlikely(denied)) {
+		audited = denied & avd->auditdeny;
+		/*
+		 * auditdeny is TRICKY!  Setting a bit in
+		 * this field means that ANY denials should NOT be audited if
+		 * the policy contains an explicit dontaudit rule for that
+		 * permission.  Take notice that this is unrelated to the
+		 * actual permissions that were denied.  As an example lets
+		 * assume:
+		 *
+		 * denied == READ
+		 * avd.auditdeny & ACCESS == 0 (not set means explicit rule)
+		 * auditdeny & ACCESS == 1
+		 *
+		 * We will NOT audit the denial even though the denied
+		 * permission was READ and the auditdeny checks were for
+		 * ACCESS
+		 */
+		if (auditdeny && !(auditdeny & avd->auditdeny))
+			audited = 0;
+	} else if (result)
+		audited = denied = requested;
+	else
+		audited = requested & avd->auditallow;
+	*deniedp = denied;
+	return audited;
+}
+
+int slow_avc_audit(u32 ssid, u32 tsid, u16 tclass,
+		   u32 requested, u32 audited, u32 denied,
+		   struct common_audit_data *a,
+		   unsigned flags);
+
+/**
+ * avc_audit - Audit the granting or denial of permissions.
+ * @ssid: source security identifier
+ * @tsid: target security identifier
+ * @tclass: target security class
+ * @requested: requested permissions
+ * @avd: access vector decisions
+ * @result: result from avc_has_perm_noaudit
+ * @a:  auxiliary audit data
+ * @flags: VFS walk flags
+ *
+ * Audit the granting or denial of permissions in accordance
+ * with the policy.  This function is typically called by
+ * avc_has_perm() after a permission check, but can also be
+ * called directly by callers who use avc_has_perm_noaudit()
+ * in order to separate the permission check from the auditing.
+ * For example, this separation is useful when the permission check must
+ * be performed under a lock, to allow the lock to be released
+ * before calling the auditing code.
+ */
+static inline int avc_audit(u32 ssid, u32 tsid,
+			    u16 tclass, u32 requested,
+			    struct av_decision *avd,
+			    int result,
+			    struct common_audit_data *a, unsigned flags)
+{
+	u32 audited, denied;
+	audited = avc_audit_required(requested, avd, result,
+				     a ? a->selinux_audit_data->auditdeny : 0,
+				     &denied);
+	if (likely(!audited))
+		return 0;
+	return slow_avc_audit(ssid, tsid, tclass,
+			      requested, audited, denied,
+			      a, flags);
+}
 
 #define AVC_STRICT 1 /* Ignore permissive mode. */
 int avc_has_perm_noaudit(u32 ssid, u32 tsid,