Fixed MTP to work with TWRP

security/apparmor/resource.c

@@ -0,0 +1,154 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor resource mediation and attachment
+ *
+ * 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/audit.h>
+
+#include "include/audit.h"
+#include "include/context.h"
+#include "include/resource.h"
+#include "include/policy.h"
+
+/*
+ * Table of rlimit names: we generate it from resource.h.
+ */
+#include "rlim_names.h"
+
+struct aa_fs_entry aa_fs_entry_rlimit[] = {
+	AA_FS_FILE_STRING("mask", AA_FS_RLIMIT_MASK),
+	{ }
+};
+
+/* audit callback for resource specific fields */
+static void audit_cb(struct audit_buffer *ab, void *va)
+{
+	struct common_audit_data *sa = va;
+
+	audit_log_format(ab, " rlimit=%s value=%lu",
+			 rlim_names[sa->aad->rlim.rlim], sa->aad->rlim.max);
+}
+
+/**
+ * audit_resource - audit setting resource limit
+ * @profile: profile being enforced  (NOT NULL)
+ * @resoure: rlimit being auditing
+ * @value: value being set
+ * @error: error value
+ *
+ * Returns: 0 or sa->error else other error code on failure
+ */
+static int audit_resource(struct aa_profile *profile, unsigned int resource,
+			  unsigned long value, int error)
+{
+	struct common_audit_data sa;
+	struct apparmor_audit_data aad = {0,};
+
+	sa.type = LSM_AUDIT_DATA_NONE;
+	sa.aad = &aad;
+	aad.op = OP_SETRLIMIT,
+	aad.rlim.rlim = resource;
+	aad.rlim.max = value;
+	aad.error = error;
+	return aa_audit(AUDIT_APPARMOR_AUTO, profile, GFP_KERNEL, &sa,
+			audit_cb);
+}
+
+/**
+ * aa_map_resouce - map compiled policy resource to internal #
+ * @resource: flattened policy resource number
+ *
+ * Returns: resource # for the current architecture.
+ *
+ * rlimit resource can vary based on architecture, map the compiled policy
+ * resource # to the internal representation for the architecture.
+ */
+int aa_map_resource(int resource)
+{
+	return rlim_map[resource];
+}
+
+/**
+ * aa_task_setrlimit - test permission to set an rlimit
+ * @profile - profile confining the task  (NOT NULL)
+ * @task - task the resource is being set on
+ * @resource - the resource being set
+ * @new_rlim - the new resource limit  (NOT NULL)
+ *
+ * Control raising the processes hard limit.
+ *
+ * Returns: 0 or error code if setting resource failed
+ */
+int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *task,
+		      unsigned int resource, struct rlimit *new_rlim)
+{
+	struct aa_profile *task_profile;
+	int error = 0;
+
+	rcu_read_lock();
+	task_profile = aa_get_profile(aa_cred_profile(__task_cred(task)));
+	rcu_read_unlock();
+
+	/* TODO: extend resource control to handle other (non current)
+	 * profiles.  AppArmor rules currently have the implicit assumption
+	 * that the task is setting the resource of a task confined with
+	 * the same profile.
+	 */
+	if (profile != task_profile ||
+	    (profile->rlimits.mask & (1 << resource) &&
+	     new_rlim->rlim_max > profile->rlimits.limits[resource].rlim_max))
+		error = -EACCES;
+
+	aa_put_profile(task_profile);
+
+	return audit_resource(profile, resource, new_rlim->rlim_max, error);
+}
+
+/**
+ * __aa_transition_rlimits - apply new profile rlimits
+ * @old: old profile on task  (NOT NULL)
+ * @new: new profile with rlimits to apply  (NOT NULL)
+ */
+void __aa_transition_rlimits(struct aa_profile *old, struct aa_profile *new)
+{
+	unsigned int mask = 0;
+	struct rlimit *rlim, *initrlim;
+	int i;
+
+	/* for any rlimits the profile controlled reset the soft limit
+	 * to the less of the tasks hard limit and the init tasks soft limit
+	 */
+	if (old->rlimits.mask) {
+		for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) {
+			if (old->rlimits.mask & mask) {
+				rlim = current->signal->rlim + i;
+				initrlim = init_task.signal->rlim + i;
+				rlim->rlim_cur = min(rlim->rlim_max,
+						     initrlim->rlim_cur);
+			}
+		}
+	}
+
+	/* set any new hard limits as dictated by the new profile */
+	if (!new->rlimits.mask)
+		return;
+	for (i = 0, mask = 1; i < RLIM_NLIMITS; i++, mask <<= 1) {
+		if (!(new->rlimits.mask & mask))
+			continue;
+
+		rlim = current->signal->rlim + i;
+		rlim->rlim_max = min(rlim->rlim_max,
+				     new->rlimits.limits[i].rlim_max);
+		/* soft limit should not exceed hard limit */
+		rlim->rlim_cur = min(rlim->rlim_cur, rlim->rlim_max);
+	}
+}