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mirror of https://gitlab.com/apparmor/apparmor synced 2025-08-22 18:17:09 +00:00
apparmor/parser/parser_common.c
John Johansen e08eaa39e2 Fix profile loads from cache files that contain multiple profiles
v3: fix freeing of filename when undefined
v2: address tyhicks feedback
    refactor to have a common write routine
    fix issue with set profile load being done even if !kernel_load

Profile loads from cache files that contain multiple profiles can
result in multiple reloads of the same profile or error messages about
failure to load profiles if the --add option is used. eg.

  apparmor="STATUS" operation="profile_load"
  name="/usr/lib/apache2/mpm-prefork/apache2" pid=8631
  comm="apparmor_parser"
  <sth0R> [82932.058388] type=1400 audit(1395415826.937:616):
  apparmor="STATUS" operation="profile_load" name="DEFAULT_URI" pid=8631
  comm="apparmor_parser"
  <sth0R> [82932.058391] type=1400 audit(1395415826.937:617):
  apparmor="STATUS" operation="profile_load"
  name="HANDLING_UNTRUSTED_INPUT" pid=8631 comm="apparmor_parser"
  <sth0R> [82932.058394] type=1400 audit(1395415826.937:618):
  apparmor="STATUS" operation="profile_load" name="phpsysinfo" pid=8631
  comm="apparmor_parser"
  <sth0R> [82932.059058] type=1400 audit(1395415826.937:619):
  apparmor="STATUS" operation="profile_replace" info="profile can not be
  replaced" error=-17
  name="/usr/lib/apache2/mpm-prefork/apache2//DEFAULT_URI" pid=8631
  comm="apparmor_parser"
  <sth0R> [82932.059574] type=1400 audit(1395415826.937:620):
  apparmor="STATUS" operation="profile_replace" info="profile can not be
  replaced" error=-17
  name="/usr/lib/apache2/mpm-prefork/apache2//HANDLING_UNTRUSTED_INPUT"
  pid=8631 comm="apparmor_parser"


The reason this happens is that the cache file is a container that
can contain multiple profiles in sequential order
  profile1
  profile2
  profile3

The parser loads the entire cache file to memory and the writes the
whole file to the kernel interface. It then skips foward in the file
to the next profile and reloads the file from that profile into
the kernel.
  eg. First load
    profile1
    profile2
    profile3

  advance to profile2, do second load
    profile2
    profile3

  advance to profile3, do third load
    profile3


With older kernels the interface would stop after the first profile and
return that it had processed the whole file, thus while wasting compute
resources copying extra data no errors occurred. However newer kernels
now support atomic loading of multipe profiles, so that all the profiles
passed in to the interface get processed.

This means on newer kernels the current parser load behavior results
in multiple loads/replacements when a cache file contains more than
one profile (note: loads from a compile do not have this problem).

To fix this, detect if the kernel supports atomic set loads, and load
the cache file once. If it doesn't only load one profile section
from a cache file at a time.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-05-08 09:03:13 -07:00

121 lines
4.2 KiB
C

/*
* Copyright (c) 2010 - 2012
* Canonical Ltd. (All rights reserved)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, contact Novell, Inc. or Canonical,
* Ltd.
*/
#include <stdlib.h>
#include <stdarg.h>
#include <libintl.h>
#include <locale.h>
#define _(s) gettext(s)
#include "parser.h"
/* Policy versioning is determined by a combination of 3 values:
* policy_version: version of txt policy
* parser_abi_version: version of abi revision of policy generated by parser
* kernel_abi_version: version of abi revision for the kernel
*
* The version info is stored in a single 32 bit version field in the
* header portion of each binary policy file.
*
* policy_version:
* a gross revision number indicating what features and semantics are
* expected by the text policy. This does not necessarily map directly
* to a feature set as a kernel may not have all the supported features
* patched/builtin.
*
* policy_version is not supported by kernels that only support v5
* kernel abi, so it will not be written when creating policy for
* those kernels.
*
* kernel_abi_version:
* should be set to the highest version supported by both the parser and
* the kernel.
* This allows new kernels to detect old userspaces, and new parsers
* to support old kernels and policies semantics.
*
* parser_abi_version:
* should be bumped when a compiler error or some other event happens
* and policy cache needs to be forced to be recomputed, when the
* policy_version or kernel version has not changed.
*
* parser_abi_version is not supported by kernels that only support
* v5 kernel abi so it will not be written when creating policy for those
* kernels.
*
* Default values set to v5 kernel abi before the different versioning
* numbers where supported.
*/
uint32_t policy_version = 2;
uint32_t parser_abi_version = 0;
uint32_t kernel_abi_version = 5;
int force_complain = 0;
int perms_create = 0; /* perms contain create flag */
int net_af_max_override = -1; /* use kernel to determine af_max */
int kernel_load = 1;
int kernel_supports_setload = 0; /* kernel supports atomic set loads */
int kernel_supports_network = 0; /* kernel supports network rules */
int kernel_supports_policydb = 0; /* kernel supports new policydb */
int kernel_supports_mount = 0; /* kernel supports mount rules */
int kernel_supports_dbus = 0; /* kernel supports dbus rules */
int kernel_supports_diff_encode = 0; /* kernel supports diff_encode */
int kernel_supports_signal = 0; /* kernel supports signal rules */
int kernel_supports_ptrace = 0; /* kernel supports ptrace rules */
int conf_verbose = 0;
int conf_quiet = 0;
int names_only = 0;
int current_lineno = 1;
int option = OPTION_ADD;
dfaflags_t dfaflags = (dfaflags_t)(DFA_CONTROL_TREE_NORMAL | DFA_CONTROL_TREE_SIMPLE | DFA_CONTROL_MINIMIZE | DFA_CONTROL_DIFF_ENCODE);
char *subdomainbase = NULL;
const char *progname = __FILE__;
char *profile_ns = NULL;
char *profilename = NULL;
char *current_filename = NULL;
FILE *ofile = NULL;
#ifdef FORCE_READ_IMPLIES_EXEC
int read_implies_exec = 1;
#else
int read_implies_exec = 0;
#endif
void pwarn(const char *fmt, ...)
{
va_list arg;
char *newfmt;
if (conf_quiet || names_only || option == OPTION_REMOVE)
return;
if (asprintf(&newfmt, _("Warning from %s (%s%sline %d): %s"),
profilename ? profilename : "stdin",
current_filename ? current_filename : "",
current_filename ? " " : "",
current_lineno,
fmt) == -1)
return;
va_start(arg, fmt);
vfprintf(stderr, newfmt, arg);
va_end(arg);
free(newfmt);
}