// SPDX-License-Identifier: GPL-2.0-only/* * AppArmor security module * * This file contains AppArmor resource mediation and attachment * * Copyright (C) 1998-2008 Novell/SUSE * Copyright 2009-2010 Canonical Ltd. */ #include <linux/audit.h>#include <linux/security.h> #include "include/audit.h"#include "include/cred.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_sfs_entry aa_sfs_entry_rlimit[] = {	AA_SFS_FILE_STRING("mask", AA_SFS_RLIMIT_MASK),	{ }}; /* audit callback for resource specific fields */static void audit_cb(struct audit_buffer *ab, void *va){	struct common_audit_data *sa = va;	struct apparmor_audit_data *ad = aad(sa); 	audit_log_format(ab, " rlimit=%s value=%lu",			 rlim_names[ad->rlim.rlim], ad->rlim.max);	if (ad->peer) {		audit_log_format(ab, " peer=");		aa_label_xaudit(ab, labels_ns(ad->subj_label), ad->peer,				FLAGS_NONE, GFP_ATOMIC);	}} /** * audit_resource - audit setting resource limit * @subj_cred: cred setting the resource * @profile: profile being enforced  (NOT NULL) * @resource: rlimit being auditing * @value: value being set * @peer: aa_albel of the task being set * @info: info being auditing * @error: error value * * Returns: 0 or ad->error else other error code on failure */static int audit_resource(const struct cred *subj_cred,			  struct aa_profile *profile, unsigned int resource,			  unsigned long value, struct aa_label *peer,			  const char *info, int error){	DEFINE_AUDIT_DATA(ad, LSM_AUDIT_DATA_NONE, AA_CLASS_RLIMITS,			  OP_SETRLIMIT); 	ad.subj_cred = subj_cred;	ad.rlim.rlim = resource;	ad.rlim.max = value;	ad.peer = peer;	ad.info = info;	ad.error = error; 	return aa_audit(AUDIT_APPARMOR_AUTO, profile, &ad, audit_cb);} /** * aa_map_resource - 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];} static int profile_setrlimit(const struct cred *subj_cred,			     struct aa_profile *profile, unsigned int resource,			     struct rlimit *new_rlim){	struct aa_ruleset *rules = profile->label.rules[0];	int e = 0; 	if (rules->rlimits.mask & (1 << resource) && new_rlim->rlim_max >	    rules->rlimits.limits[resource].rlim_max)		e = -EACCES;	return audit_resource(subj_cred, profile, resource, new_rlim->rlim_max,			      NULL, NULL, e);} /** * aa_task_setrlimit - test permission to set an rlimit * @subj_cred: cred setting the limit * @label: label 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(const struct cred *subj_cred, struct aa_label *label,		      struct task_struct *task,		      unsigned int resource, struct rlimit *new_rlim){	struct aa_profile *profile;	struct aa_label *peer;	int error = 0; 	rcu_read_lock();	peer = aa_get_newest_cred_label(__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 or that the task setting the resource of another	 * task has CAP_SYS_RESOURCE.	 */ 	if (label != peer &&	    aa_capable(subj_cred, label, CAP_SYS_RESOURCE, CAP_OPT_NOAUDIT) != 0)		error = fn_for_each(label, profile,				audit_resource(subj_cred, profile, resource,					       new_rlim->rlim_max, peer,					       "cap_sys_resource", -EACCES));	else		error = fn_for_each_confined(label, profile,				profile_setrlimit(subj_cred, profile, resource,						  new_rlim));	aa_put_label(peer); 	return error;} /** * __aa_transition_rlimits - apply new profile rlimits * @old_l: old label on task  (NOT NULL) * @new_l: new label with rlimits to apply  (NOT NULL) */void __aa_transition_rlimits(struct aa_label *old_l, struct aa_label *new_l){	unsigned int mask = 0;	struct rlimit *rlim, *initrlim;	struct aa_profile *old, *new;	struct label_it i; 	old = labels_profile(old_l);	new = labels_profile(new_l); 	/* for any rlimits the profile controlled, reset the soft limit	 * to the lesser of the tasks hard limit and the init tasks soft limit	 */	label_for_each_confined(i, old_l, old) {		struct aa_ruleset *rules = old->label.rules[0];		if (rules->rlimits.mask) {			int j; 			for (j = 0, mask = 1; j < RLIM_NLIMITS; j++,				     mask <<= 1) {				if (rules->rlimits.mask & mask) {					rlim = current->signal->rlim + j;					initrlim = init_task.signal->rlim + j;					rlim->rlim_cur = min(rlim->rlim_max,							    initrlim->rlim_cur);				}			}		}	} 	/* set any new hard limits as dictated by the new profile */	label_for_each_confined(i, new_l, new) {		struct aa_ruleset *rules = new->label.rules[0];		int j; 		if (!rules->rlimits.mask)			continue;		for (j = 0, mask = 1; j < RLIM_NLIMITS; j++, mask <<= 1) {			if (!(rules->rlimits.mask & mask))				continue; 			rlim = current->signal->rlim + j;			rlim->rlim_max = min(rlim->rlim_max,					     rules->rlimits.limits[j].rlim_max);			/* soft limit should not exceed hard limit */			rlim->rlim_cur = min(rlim->rlim_cur, rlim->rlim_max);			if (j == RLIMIT_CPU &&			    rlim->rlim_cur != RLIM_INFINITY &&			    IS_ENABLED(CONFIG_POSIX_TIMERS))				(void) update_rlimit_cpu(current->group_leader,							 rlim->rlim_cur);		}	}}