1 files changed, 114 insertions, 0 deletions
diff --git a/security/apparmor/ipc.c b/security/apparmor/ipc.c
new file mode 100644
index 000000000000..649fad88869b
--- /dev/null
+++ b/security/apparmor/ipc.c
@@ -0,0 +1,114 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor ipc mediation
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2010 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ */
+
+#include <linux/gfp.h>
+#include <linux/ptrace.h>
+
+#include "include/audit.h"
+#include "include/capability.h"
+#include "include/context.h"
+#include "include/policy.h"
+
+/* call back to audit ptrace fields */
+static void audit_cb(struct audit_buffer *ab, void *va)
+{
+	struct common_audit_data *sa = va;
+	audit_log_format(ab, " target=");
+	audit_log_untrustedstring(ab, sa->aad.target);
+}
+
+/**
+ * aa_audit_ptrace - do auditing for ptrace
+ * @profile: profile being enforced  (NOT NULL)
+ * @target: profile being traced (NOT NULL)
+ * @error: error condition
+ *
+ * Returns: %0 or error code
+ */
+static int aa_audit_ptrace(struct aa_profile *profile,
+			   struct aa_profile *target, int error)
+{
+	struct common_audit_data sa;
+	COMMON_AUDIT_DATA_INIT(&sa, NONE);
+	sa.aad.op = OP_PTRACE;
+	sa.aad.target = target;
+	sa.aad.error = error;
+
+	return aa_audit(AUDIT_APPARMOR_AUTO, profile, GFP_ATOMIC, &sa,
+			audit_cb);
+}
+
+/**
+ * aa_may_ptrace - test if tracer task can trace the tracee
+ * @tracer_task: task who will do the tracing  (NOT NULL)
+ * @tracer: profile of the task doing the tracing  (NOT NULL)
+ * @tracee: task to be traced
+ * @mode: whether PTRACE_MODE_READ || PTRACE_MODE_ATTACH
+ *
+ * Returns: %0 else error code if permission denied or error
+ */
+int aa_may_ptrace(struct task_struct *tracer_task, struct aa_profile *tracer,
+		  struct aa_profile *tracee, unsigned int mode)
+{
+	/* TODO: currently only based on capability, not extended ptrace
+	 *       rules,
+	 *       Test mode for PTRACE_MODE_READ || PTRACE_MODE_ATTACH
+	 */
+
+	if (unconfined(tracer) || tracer == tracee)
+		return 0;
+	/* log this capability request */
+	return aa_capable(tracer_task, tracer, CAP_SYS_PTRACE, 1);
+}
+
+/**
+ * aa_ptrace - do ptrace permission check and auditing
+ * @tracer: task doing the tracing (NOT NULL)
+ * @tracee: task being traced (NOT NULL)
+ * @mode: ptrace mode either PTRACE_MODE_READ || PTRACE_MODE_ATTACH
+ *
+ * Returns: %0 else error code if permission denied or error
+ */
+int aa_ptrace(struct task_struct *tracer, struct task_struct *tracee,
+	      unsigned int mode)
+{
+	/*
+	 * tracer can ptrace tracee when
+	 * - tracer is unconfined ||
+	 *   - tracer is in complain mode
+	 *   - tracer has rules allowing it to trace tracee currently this is:
+	 *       - confined by the same profile ||
+	 *       - tracer profile has CAP_SYS_PTRACE
+	 */
+
+	struct aa_profile *tracer_p;
+	/* cred released below */
+	const struct cred *cred = get_task_cred(tracer);
+	int error = 0;
+	tracer_p = aa_cred_profile(cred);
+
+	if (!unconfined(tracer_p)) {
+		/* lcred released below */
+		const struct cred *lcred = get_task_cred(tracee);
+		struct aa_profile *tracee_p = aa_cred_profile(lcred);
+
+		error = aa_may_ptrace(tracer, tracer_p, tracee_p, mode);
+		error = aa_audit_ptrace(tracer_p, tracee_p, error);
+
+		put_cred(lcred);
+	}
+	put_cred(cred);
+
+	return error;
+}