// 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; }