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-rw-r--r--security/apparmor/capability.c158
1 files changed, 158 insertions, 0 deletions
diff --git a/security/apparmor/capability.c b/security/apparmor/capability.c
new file mode 100644
index 000000000..deccea865
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+++ b/security/apparmor/capability.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor capability mediation functions
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2010 Canonical Ltd.
+ */
+
+#include <linux/capability.h>
+#include <linux/errno.h>
+#include <linux/gfp.h>
+#include <linux/security.h>
+
+#include "include/apparmor.h"
+#include "include/capability.h"
+#include "include/cred.h"
+#include "include/policy.h"
+#include "include/audit.h"
+
+/*
+ * Table of capability names: we generate it from capabilities.h.
+ */
+#include "capability_names.h"
+
+struct aa_sfs_entry aa_sfs_entry_caps[] = {
+ AA_SFS_FILE_STRING("mask", AA_SFS_CAPS_MASK),
+ { }
+};
+
+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
+ * @sa: audit data
+ * @profile: profile being tested for confinement (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 common_audit_data *sa, struct aa_profile *profile,
+ int cap, int error)
+{
+ struct audit_cache *ent;
+ int type = AUDIT_APPARMOR_AUTO;
+
+ aad(sa)->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, 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
+ * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated
+ * @sa: audit data (MAY BE NULL indicating no auditing)
+ *
+ * Returns: 0 if allowed else -EPERM
+ */
+static int profile_capable(struct aa_profile *profile, int cap,
+ unsigned int opts, struct common_audit_data *sa)
+{
+ int error;
+
+ if (cap_raised(profile->caps.allow, cap) &&
+ !cap_raised(profile->caps.denied, cap))
+ error = 0;
+ else
+ error = -EPERM;
+
+ if (opts & CAP_OPT_NOAUDIT) {
+ if (!COMPLAIN_MODE(profile))
+ return error;
+ /* audit the cap request in complain mode but note that it
+ * should be optional.
+ */
+ aad(sa)->info = "optional: no audit";
+ }
+
+ return audit_caps(sa, profile, cap, error);
+}
+
+/**
+ * aa_capable - test permission to use capability
+ * @label: label being tested for capability (NOT NULL)
+ * @cap: capability to be tested
+ * @opts: CAP_OPT_NOAUDIT bit determines whether audit record is generated
+ *
+ * Look up capability in profile capability set.
+ *
+ * Returns: 0 on success, or else an error code.
+ */
+int aa_capable(struct aa_label *label, int cap, unsigned int opts)
+{
+ struct aa_profile *profile;
+ int error = 0;
+ DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_CAP, OP_CAPABLE);
+
+ sa.u.cap = cap;
+ error = fn_for_each_confined(label, profile,
+ profile_capable(profile, cap, opts, &sa));
+
+ return error;
+}