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-rw-r--r--security/apparmor/resource.c154
1 files changed, 154 insertions, 0 deletions
diff --git a/security/apparmor/resource.c b/security/apparmor/resource.c
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+++ b/security/apparmor/resource.c
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+/*
+ * 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);
+ }
+}