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-rw-r--r--security/apparmor/capability.c141
1 files changed, 141 insertions, 0 deletions
diff --git a/security/apparmor/capability.c b/security/apparmor/capability.c
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+++ b/security/apparmor/capability.c
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+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor capability mediation functions
+ *
+ * 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/capability.h>
+#include <linux/errno.h>
+#include <linux/gfp.h>
+
+#include "include/apparmor.h"
+#include "include/capability.h"
+#include "include/context.h"
+#include "include/policy.h"
+#include "include/audit.h"
+
+/*
+ * Table of capability names: we generate it from capabilities.h.
+ */
+#include "capability_names.h"
+
+struct audit_cache {
+ struct aa_profile *profile;
+ kernel_cap_t caps;
+};
+
+static DEFINE_PER_CPU(struct audit_cache, audit_cache);
+
+/**
+ * audit_cb - call back for capability components of audit struct
+ * @ab - audit buffer (NOT NULL)
+ * @va - audit struct to audit data from (NOT NULL)
+ */
+static void audit_cb(struct audit_buffer *ab, void *va)
+{
+ struct common_audit_data *sa = va;
+ audit_log_format(ab, " capname=");
+ audit_log_untrustedstring(ab, capability_names[sa->u.cap]);
+}
+
+/**
+ * audit_caps - audit a capability
+ * @profile: profile confining task (NOT NULL)
+ * @task: task capability test was performed against (NOT NULL)
+ * @cap: capability tested
+ * @error: error code returned by test
+ *
+ * Do auditing of capability and handle, audit/complain/kill modes switching
+ * and duplicate message elimination.
+ *
+ * Returns: 0 or sa->error on success, error code on failure
+ */
+static int audit_caps(struct aa_profile *profile, struct task_struct *task,
+ int cap, int error)
+{
+ struct audit_cache *ent;
+ int type = AUDIT_APPARMOR_AUTO;
+ struct common_audit_data sa;
+ COMMON_AUDIT_DATA_INIT(&sa, CAP);
+ sa.tsk = task;
+ sa.u.cap = cap;
+ sa.aad.op = OP_CAPABLE;
+ sa.aad.error = error;
+
+ if (likely(!error)) {
+ /* test if auditing is being forced */
+ if (likely((AUDIT_MODE(profile) != AUDIT_ALL) &&
+ !cap_raised(profile->caps.audit, cap)))
+ return 0;
+ type = AUDIT_APPARMOR_AUDIT;
+ } else if (KILL_MODE(profile) ||
+ cap_raised(profile->caps.kill, cap)) {
+ type = AUDIT_APPARMOR_KILL;
+ } else if (cap_raised(profile->caps.quiet, cap) &&
+ AUDIT_MODE(profile) != AUDIT_NOQUIET &&
+ AUDIT_MODE(profile) != AUDIT_ALL) {
+ /* quiet auditing */
+ return error;
+ }
+
+ /* Do simple duplicate message elimination */
+ ent = &get_cpu_var(audit_cache);
+ if (profile == ent->profile && cap_raised(ent->caps, cap)) {
+ put_cpu_var(audit_cache);
+ if (COMPLAIN_MODE(profile))
+ return complain_error(error);
+ return error;
+ } else {
+ aa_put_profile(ent->profile);
+ ent->profile = aa_get_profile(profile);
+ cap_raise(ent->caps, cap);
+ }
+ put_cpu_var(audit_cache);
+
+ return aa_audit(type, profile, GFP_ATOMIC, &sa, audit_cb);
+}
+
+/**
+ * profile_capable - test if profile allows use of capability @cap
+ * @profile: profile being enforced (NOT NULL, NOT unconfined)
+ * @cap: capability to test if allowed
+ *
+ * Returns: 0 if allowed else -EPERM
+ */
+static int profile_capable(struct aa_profile *profile, int cap)
+{
+ return cap_raised(profile->caps.allow, cap) ? 0 : -EPERM;
+}
+
+/**
+ * aa_capable - test permission to use capability
+ * @task: task doing capability test against (NOT NULL)
+ * @profile: profile confining @task (NOT NULL)
+ * @cap: capability to be tested
+ * @audit: whether an audit record should be generated
+ *
+ * Look up capability in profile capability set.
+ *
+ * Returns: 0 on success, or else an error code.
+ */
+int aa_capable(struct task_struct *task, struct aa_profile *profile, int cap,
+ int audit)
+{
+ int error = profile_capable(profile, cap);
+
+ if (!audit) {
+ if (COMPLAIN_MODE(profile))
+ return complain_error(error);
+ return error;
+ }
+
+ return audit_caps(profile, task, cap, error);
+}