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Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224// 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;}