selinux/semodule-utils/semodule_link/semodule_link.c
Christian Göttsche 8547846ecd semodule_link: avoid NULL dereference on OOM
In case the initial calloc(3) call fails the variable mods is still NULL
while its size hint num_mods is set.

Reported by Clang Analyzer:

    semodule_link.c:182:29: warning: Array access (from variable 'mods') results in a null pointer dereference [core.NullDereference]
      182 |                 sepol_module_package_free(mods[i]);
          |                                           ^~~~~~~

Fixes: 63e798a203 ("semodule_link: update")

Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: James Carter <jwcart2@gmail.com>
2023-11-15 08:38:39 -05:00

190 lines
4.2 KiB
C

/* Authors: Karl MacMillan <kmacmillan@tresys.com>
*
* Copyright (C) 2004 Tresys Technology, LLC
* 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.
*/
#include <sepol/module.h>
#include <getopt.h>
#include <fcntl.h>
#include <stdio.h>
#include <errno.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#define LINKPOLICY_VERSION "1.0"
static void usage(const char *program_name)
{
printf("usage: %s [-hVv] [-o outfile] basemodpkg modpkg1 [modpkg2]...\n",
program_name);
}
static sepol_module_package_t *load_module(const char *filename, const char *progname)
{
int ret;
FILE *fp = NULL;
struct sepol_policy_file *pf = NULL;
sepol_module_package_t *p = NULL;
if (sepol_module_package_create(&p)) {
fprintf(stderr, "%s: Out of memory\n", progname);
goto bad;
}
if (sepol_policy_file_create(&pf)) {
fprintf(stderr, "%s: Out of memory\n", progname);
goto bad;
}
fp = fopen(filename, "re");
if (!fp) {
fprintf(stderr, "%s: Could not open package %s: %s\n", progname,
filename, strerror(errno));
goto bad;
}
sepol_policy_file_set_fp(pf, fp);
printf("%s: loading package from file %s\n", progname, filename);
ret = sepol_module_package_read(p, pf, 0);
if (ret) {
fprintf(stderr, "%s: Error while reading package from %s\n",
progname, filename);
goto bad;
}
fclose(fp);
sepol_policy_file_free(pf);
return p;
bad:
sepol_module_package_free(p);
sepol_policy_file_free(pf);
if (fp)
fclose(fp);
return NULL;
}
int main(int argc, char **argv)
{
int ch, i, ret, show_version = 0, verbose = 0, num_mods = 0;
const char *basename, *outname = NULL;
sepol_module_package_t *base = NULL, **mods = NULL;
struct sepol_policy_file *pf = NULL;
while ((ch = getopt(argc, argv, "ho:Vv")) != EOF) {
switch (ch) {
case 'h':
usage(argv[0]);
return EXIT_SUCCESS;
case 'V':
show_version = 1;
break;
case 'v':
verbose = 1;
break;
case 'o':
outname = optarg;
break;
default:
usage(argv[0]);
return EXIT_FAILURE;
}
}
if (show_version) {
printf("%s\n", LINKPOLICY_VERSION);
return EXIT_SUCCESS;
}
/* check args */
if (argc < 3 || optind + 2 > argc) {
fprintf(stderr,
"%s: You must provide the base module package and at least one other module package\n",
argv[0]);
usage(argv[0]);
return EXIT_FAILURE;
}
basename = argv[optind++];
base = load_module(basename, argv[0]);
if (!base) {
fprintf(stderr,
"%s: Could not load base module from file %s\n",
argv[0], basename);
goto failure;
}
num_mods = argc - optind;
mods = calloc(num_mods, sizeof(sepol_module_package_t *));
if (!mods) {
fprintf(stderr, "%s: Out of memory\n", argv[0]);
goto failure;
}
for (i = 0; optind < argc; optind++, i++) {
mods[i] = load_module(argv[optind], argv[0]);
if (!mods[i]) {
fprintf(stderr,
"%s: Could not load module from file %s\n",
argv[0], argv[optind]);
goto failure;
}
}
if (sepol_link_packages(NULL, base, mods, num_mods, verbose)) {
fprintf(stderr, "%s: Error while linking packages\n", argv[0]);
goto failure;
}
if (outname) {
FILE *outfile = fopen(outname, "we");
if (!outfile) {
fprintf(stderr, "%s: Could not open output file %s: %s\n",
argv[0], outname, strerror(errno));
goto failure;
}
if (sepol_policy_file_create(&pf)) {
fprintf(stderr, "%s: Out of memory\n", argv[0]);
fclose(outfile);
goto failure;
}
sepol_policy_file_set_fp(pf, outfile);
if (sepol_module_package_write(base, pf)) {
fprintf(stderr, "%s: Error writing linked package.\n",
argv[0]);
sepol_policy_file_free(pf);
fclose(outfile);
goto failure;
}
sepol_policy_file_free(pf);
if (fclose(outfile)) {
fprintf(stderr, "%s: Error closing linked package: %s\n",
argv[0], strerror(errno));
goto failure;
}
}
ret = EXIT_SUCCESS;
goto cleanup;
failure:
ret = EXIT_FAILURE;
cleanup:
if (mods) {
for (i = 0; i < num_mods; i++)
sepol_module_package_free(mods[i]);
free(mods);
}
sepol_module_package_free(base);
return ret;
}