// 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 <linux/timekeeping.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),	AA_SFS_FILE_BOOLEAN("extended", 1),	{ }}; struct audit_cache {	const struct cred *ad_subj_cred;	/* Capabilities go from 0 to CAP_LAST_CAP */	u64 ktime_ns_expiration[CAP_LAST_CAP+1];}; 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 * @ad: 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 ad->error on success,  error code on failure */static int audit_caps(struct apparmor_audit_data *ad, struct aa_profile *profile,		      int cap, int error){	const u64 AUDIT_CACHE_TIMEOUT_NS = 1000*1000*1000; /* 1 second */ 	struct aa_ruleset *rules = profile->label.rules[0];	struct audit_cache *ent;	int type = AUDIT_APPARMOR_AUTO; 	ad->error = error; 	if (likely(!error)) {		/* test if auditing is being forced */		if (likely((AUDIT_MODE(profile) != AUDIT_ALL) &&			   !cap_raised(rules->caps.audit, cap)))			return 0;		type = AUDIT_APPARMOR_AUDIT;	} else if (KILL_MODE(profile) ||		   cap_raised(rules->caps.kill, cap)) {		type = AUDIT_APPARMOR_KILL;	} else if (cap_raised(rules->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 the capability was never raised the timestamp check would also catch that */	if (ad->subj_cred == ent->ad_subj_cred && ktime_get_ns() <= ent->ktime_ns_expiration[cap]) {		put_cpu_var(audit_cache);		if (COMPLAIN_MODE(profile))			return complain_error(error);		return error;	} else {		put_cred(ent->ad_subj_cred);		ent->ad_subj_cred = get_cred(ad->subj_cred);		ent->ktime_ns_expiration[cap] = ktime_get_ns() + AUDIT_CACHE_TIMEOUT_NS;	}	put_cpu_var(audit_cache); 	return aa_audit(type, profile, ad, 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 * @ad: audit data (NOT NULL) * * Returns: 0 if allowed else -EPERM */static int profile_capable(struct aa_profile *profile, int cap,			   unsigned int opts, struct apparmor_audit_data *ad){	struct aa_ruleset *rules = profile->label.rules[0];	aa_state_t state;	int error; 	state = RULE_MEDIATES(rules, ad->class);	if (state) {		struct aa_perms perms = { };		u32 request; 		/* caps broken into 256 x 32 bit permission chunks */		state = aa_dfa_next(rules->policy->dfa, state, cap >> 5);		request = 1 << (cap & 0x1f);		perms = *aa_lookup_perms(rules->policy, state);		aa_apply_modes_to_perms(profile, &perms); 		if (opts & CAP_OPT_NOAUDIT) {			if (perms.complain & request)				ad->info = "optional: no audit";			else				ad = NULL;		}		return aa_check_perms(profile, &perms, request, ad,				      audit_cb);	} 	/* fallback to old caps mediation that doesn't support conditionals */	if (cap_raised(rules->caps.allow, cap) &&	    !cap_raised(rules->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.		 */		ad->info = "optional: no audit";	} 	return audit_caps(ad, profile, cap, error);} /** * aa_capable - test permission to use capability * @subj_cred: cred we are testing capability against * @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(const struct cred *subj_cred, struct aa_label *label,	       int cap, unsigned int opts){	struct aa_profile *profile;	int error = 0;	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_CAP, AA_CLASS_CAP, OP_CAPABLE); 	ad.subj_cred = subj_cred;	ad.common.u.cap = cap;	error = fn_for_each_confined(label, profile,			profile_capable(profile, cap, opts, &ad)); 	return error;} kernel_cap_t aa_profile_capget(struct aa_profile *profile){	struct aa_ruleset *rules = profile->label.rules[0];	aa_state_t state; 	state = RULE_MEDIATES(rules, AA_CLASS_CAP);	if (state) {		kernel_cap_t caps = CAP_EMPTY_SET;		int i; 		/* caps broken into up to 256, 32 bit permission chunks */		for (i = 0; i < (CAP_LAST_CAP >> 5); i++) {			struct aa_perms perms = { };			aa_state_t tmp; 			tmp = aa_dfa_next(rules->policy->dfa, state, i);			perms = *aa_lookup_perms(rules->policy, tmp);			aa_apply_modes_to_perms(profile, &perms);			caps.val |= ((u64)(perms.allow)) << (i * 5);			caps.val |= ((u64)(perms.complain)) << (i * 5);		}		return caps;	} 	/* fallback to old caps */	if (COMPLAIN_MODE(profile))		return CAP_FULL_SET; 	return rules->caps.allow;}