kernel_optimize_test/security/apparmor/ipc.c
Micah Morton c1a85a00ea LSM: generalize flag passing to security_capable
This patch provides a general mechanism for passing flags to the
security_capable LSM hook. It replaces the specific 'audit' flag that is
used to tell security_capable whether it should log an audit message for
the given capability check. The reason for generalizing this flag
passing is so we can add an additional flag that signifies whether
security_capable is being called by a setid syscall (which is needed by
the proposed SafeSetID LSM).

Signed-off-by: Micah Morton <mortonm@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
2019-01-10 14:16:06 -08:00

223 lines
6.2 KiB
C

/*
* AppArmor security module
*
* This file contains AppArmor ipc mediation
*
* Copyright (C) 1998-2008 Novell/SUSE
* Copyright 2009-2017 Canonical Ltd.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation, version 2 of the
* License.
*/
#include <linux/gfp.h>
#include <linux/ptrace.h>
#include "include/audit.h"
#include "include/capability.h"
#include "include/cred.h"
#include "include/policy.h"
#include "include/ipc.h"
#include "include/sig_names.h"
/**
* audit_ptrace_mask - convert mask to permission string
* @buffer: buffer to write string to (NOT NULL)
* @mask: permission mask to convert
*/
static void audit_ptrace_mask(struct audit_buffer *ab, u32 mask)
{
switch (mask) {
case MAY_READ:
audit_log_string(ab, "read");
break;
case MAY_WRITE:
audit_log_string(ab, "trace");
break;
case AA_MAY_BE_READ:
audit_log_string(ab, "readby");
break;
case AA_MAY_BE_TRACED:
audit_log_string(ab, "tracedby");
break;
}
}
/* call back to audit ptrace fields */
static void audit_ptrace_cb(struct audit_buffer *ab, void *va)
{
struct common_audit_data *sa = va;
if (aad(sa)->request & AA_PTRACE_PERM_MASK) {
audit_log_format(ab, " requested_mask=");
audit_ptrace_mask(ab, aad(sa)->request);
if (aad(sa)->denied & AA_PTRACE_PERM_MASK) {
audit_log_format(ab, " denied_mask=");
audit_ptrace_mask(ab, aad(sa)->denied);
}
}
audit_log_format(ab, " peer=");
aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
FLAGS_NONE, GFP_ATOMIC);
}
/* assumes check for PROFILE_MEDIATES is already done */
/* TODO: conditionals */
static int profile_ptrace_perm(struct aa_profile *profile,
struct aa_label *peer, u32 request,
struct common_audit_data *sa)
{
struct aa_perms perms = { };
aad(sa)->peer = peer;
aa_profile_match_label(profile, peer, AA_CLASS_PTRACE, request,
&perms);
aa_apply_modes_to_perms(profile, &perms);
return aa_check_perms(profile, &perms, request, sa, audit_ptrace_cb);
}
static int profile_tracee_perm(struct aa_profile *tracee,
struct aa_label *tracer, u32 request,
struct common_audit_data *sa)
{
if (profile_unconfined(tracee) || unconfined(tracer) ||
!PROFILE_MEDIATES(tracee, AA_CLASS_PTRACE))
return 0;
return profile_ptrace_perm(tracee, tracer, request, sa);
}
static int profile_tracer_perm(struct aa_profile *tracer,
struct aa_label *tracee, u32 request,
struct common_audit_data *sa)
{
if (profile_unconfined(tracer))
return 0;
if (PROFILE_MEDIATES(tracer, AA_CLASS_PTRACE))
return profile_ptrace_perm(tracer, tracee, request, sa);
/* profile uses the old style capability check for ptrace */
if (&tracer->label == tracee)
return 0;
aad(sa)->label = &tracer->label;
aad(sa)->peer = tracee;
aad(sa)->request = 0;
aad(sa)->error = aa_capable(&tracer->label, CAP_SYS_PTRACE,
CAP_OPT_NONE);
return aa_audit(AUDIT_APPARMOR_AUTO, tracer, sa, audit_ptrace_cb);
}
/**
* aa_may_ptrace - test if tracer task can trace the tracee
* @tracer: label of the task doing the tracing (NOT NULL)
* @tracee: task label to be traced
* @request: permission request
*
* Returns: %0 else error code if permission denied or error
*/
int aa_may_ptrace(struct aa_label *tracer, struct aa_label *tracee,
u32 request)
{
struct aa_profile *profile;
u32 xrequest = request << PTRACE_PERM_SHIFT;
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_PTRACE);
return xcheck_labels(tracer, tracee, profile,
profile_tracer_perm(profile, tracee, request, &sa),
profile_tracee_perm(profile, tracer, xrequest, &sa));
}
static inline int map_signal_num(int sig)
{
if (sig > SIGRTMAX)
return SIGUNKNOWN;
else if (sig >= SIGRTMIN)
return sig - SIGRTMIN + SIGRT_BASE;
else if (sig < MAXMAPPED_SIG)
return sig_map[sig];
return SIGUNKNOWN;
}
/**
* audit_file_mask - convert mask to permission string
* @buffer: buffer to write string to (NOT NULL)
* @mask: permission mask to convert
*/
static void audit_signal_mask(struct audit_buffer *ab, u32 mask)
{
if (mask & MAY_READ)
audit_log_string(ab, "receive");
if (mask & MAY_WRITE)
audit_log_string(ab, "send");
}
/**
* audit_cb - call back for signal specific audit fields
* @ab: audit_buffer (NOT NULL)
* @va: audit struct to audit values of (NOT NULL)
*/
static void audit_signal_cb(struct audit_buffer *ab, void *va)
{
struct common_audit_data *sa = va;
if (aad(sa)->request & AA_SIGNAL_PERM_MASK) {
audit_log_format(ab, " requested_mask=");
audit_signal_mask(ab, aad(sa)->request);
if (aad(sa)->denied & AA_SIGNAL_PERM_MASK) {
audit_log_format(ab, " denied_mask=");
audit_signal_mask(ab, aad(sa)->denied);
}
}
if (aad(sa)->signal == SIGUNKNOWN)
audit_log_format(ab, "signal=unknown(%d)",
aad(sa)->unmappedsig);
else if (aad(sa)->signal < MAXMAPPED_SIGNAME)
audit_log_format(ab, " signal=%s", sig_names[aad(sa)->signal]);
else
audit_log_format(ab, " signal=rtmin+%d",
aad(sa)->signal - SIGRT_BASE);
audit_log_format(ab, " peer=");
aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
FLAGS_NONE, GFP_ATOMIC);
}
static int profile_signal_perm(struct aa_profile *profile,
struct aa_label *peer, u32 request,
struct common_audit_data *sa)
{
struct aa_perms perms;
unsigned int state;
if (profile_unconfined(profile) ||
!PROFILE_MEDIATES(profile, AA_CLASS_SIGNAL))
return 0;
aad(sa)->peer = peer;
/* TODO: secondary cache check <profile, profile, perm> */
state = aa_dfa_next(profile->policy.dfa,
profile->policy.start[AA_CLASS_SIGNAL],
aad(sa)->signal);
aa_label_match(profile, peer, state, false, request, &perms);
aa_apply_modes_to_perms(profile, &perms);
return aa_check_perms(profile, &perms, request, sa, audit_signal_cb);
}
int aa_may_signal(struct aa_label *sender, struct aa_label *target, int sig)
{
struct aa_profile *profile;
DEFINE_AUDIT_DATA(sa, LSM_AUDIT_DATA_NONE, OP_SIGNAL);
aad(&sa)->signal = map_signal_num(sig);
aad(&sa)->unmappedsig = sig;
return xcheck_labels(sender, target, profile,
profile_signal_perm(profile, target, MAY_WRITE, &sa),
profile_signal_perm(profile, sender, MAY_READ, &sa));
}