access() uses real UID instead of effective UID which causes false negative checks in setuid programs. Replace access(,F_OK) (i.e. tests for file existence) by stat(). And access(,R_OK) by fopen(,"r") Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1186431 Signed-off-by: Vit Mojzis <vmojzis@xxxxxxxxxx> --- libsemanage/src/direct_api.c | 133 +++++++++++++++++++++++++-------------- libsemanage/src/semanage_store.c | 16 ++++- 2 files changed, 99 insertions(+), 50 deletions(-) diff --git a/libsemanage/src/direct_api.c b/libsemanage/src/direct_api.c index 49cac14f..4e2af810 100644 --- a/libsemanage/src/direct_api.c +++ b/libsemanage/src/direct_api.c @@ -140,6 +140,7 @@ int semanage_direct_is_managed(semanage_handle_t * sh) int semanage_direct_connect(semanage_handle_t * sh) { const char *path; + struct stat sb; if (semanage_check_init(sh, sh->conf->store_root_path)) goto err; @@ -302,10 +303,16 @@ int semanage_direct_connect(semanage_handle_t * sh) /* set the disable dontaudit value */ path = semanage_path(SEMANAGE_ACTIVE, SEMANAGE_DISABLE_DONTAUDIT); - if (access(path, F_OK) == 0) + + if (stat(path, &sb) == 0) sepol_set_disable_dontaudit(sh->sepolh, 1); - else + else if (errno == ENOENT) { + /* The file does not exist */ sepol_set_disable_dontaudit(sh->sepolh, 0); + } else { + ERR(sh, "Unable to access %s: %s\n", path, strerror(errno)); + goto err; + } return STATUS_SUCCESS; @@ -1139,6 +1146,7 @@ static int semanage_compile_hll_modules(semanage_handle_t *sh, int status = 0; int i; char cil_path[PATH_MAX]; + struct stat sb; assert(sh); assert(modinfos); @@ -1155,9 +1163,13 @@ static int semanage_compile_hll_modules(semanage_handle_t *sh, } if (semanage_get_ignore_module_cache(sh) == 0 && - access(cil_path, F_OK) == 0) { + (status = stat(cil_path, &sb)) == 0) { continue; } + if (status != 0 && errno != ENOENT) { + ERR(sh, "Unable to access %s: %s\n", cil_path, strerror(errno)); + goto cleanup; //an error in the "stat" call + } status = semanage_compile_module(sh, &modinfos[i]); if (status < 0) { @@ -1196,6 +1208,7 @@ static int semanage_direct_commit(semanage_handle_t * sh) struct cil_db *cildb = NULL; semanage_module_info_t *modinfos = NULL; mode_t mask = umask(0077); + struct stat sb; int do_rebuild, do_write_kernel, do_install; int fcontexts_modified, ports_modified, seusers_modified, @@ -1234,10 +1247,15 @@ static int semanage_direct_commit(semanage_handle_t * sh) /* Create or remove the disable_dontaudit flag file. */ path = semanage_path(SEMANAGE_TMP, SEMANAGE_DISABLE_DONTAUDIT); - if (access(path, F_OK) == 0) + if (stat(path, &sb) == 0) do_rebuild |= !(sepol_get_disable_dontaudit(sh->sepolh) == 1); - else + else if (errno == ENOENT) { + /* The file does not exist */ do_rebuild |= (sepol_get_disable_dontaudit(sh->sepolh) == 1); + } else { + ERR(sh, "Unable to access %s: %s\n", path, strerror(errno)); + goto cleanup; + } if (sepol_get_disable_dontaudit(sh->sepolh) == 1) { FILE *touch; touch = fopen(path, "w"); @@ -1259,10 +1277,16 @@ static int semanage_direct_commit(semanage_handle_t * sh) /* Create or remove the preserve_tunables flag file. */ path = semanage_path(SEMANAGE_TMP, SEMANAGE_PRESERVE_TUNABLES); - if (access(path, F_OK) == 0) + if (stat(path, &sb) == 0) do_rebuild |= !(sepol_get_preserve_tunables(sh->sepolh) == 1); - else + else if (errno == ENOENT) { + /* The file does not exist */ do_rebuild |= (sepol_get_preserve_tunables(sh->sepolh) == 1); + } else { + ERR(sh, "Unable to access %s: %s\n", path, strerror(errno)); + goto cleanup; + } + if (sepol_get_preserve_tunables(sh->sepolh) == 1) { FILE *touch; touch = fopen(path, "w"); @@ -1299,40 +1323,24 @@ static int semanage_direct_commit(semanage_handle_t * sh) * a rebuild. */ if (!do_rebuild) { - path = semanage_path(SEMANAGE_TMP, SEMANAGE_STORE_KERNEL); - if (access(path, F_OK) != 0) { - do_rebuild = 1; - goto rebuild; - } - - path = semanage_path(SEMANAGE_TMP, SEMANAGE_STORE_FC); - if (access(path, F_OK) != 0) { - do_rebuild = 1; - goto rebuild; - } - - path = semanage_path(SEMANAGE_TMP, SEMANAGE_STORE_SEUSERS); - if (access(path, F_OK) != 0) { - do_rebuild = 1; - goto rebuild; - } - - path = semanage_path(SEMANAGE_TMP, SEMANAGE_LINKED); - if (access(path, F_OK) != 0) { - do_rebuild = 1; - goto rebuild; - } - - path = semanage_path(SEMANAGE_TMP, SEMANAGE_SEUSERS_LINKED); - if (access(path, F_OK) != 0) { - do_rebuild = 1; - goto rebuild; - } + int files[] = {SEMANAGE_STORE_KERNEL, + SEMANAGE_STORE_FC, + SEMANAGE_STORE_SEUSERS, + SEMANAGE_LINKED, + SEMANAGE_SEUSERS_LINKED, + SEMANAGE_USERS_EXTRA_LINKED}; + + for (i = 0; i < (int) sizeof(files); i++) { + path = semanage_path(SEMANAGE_TMP, files[i]); + if (stat(path, &sb) != 0) { + if (errno != ENOENT) { + ERR(sh, "Unable to access %s: %s\n", path, strerror(errno)); + goto cleanup; + } - path = semanage_path(SEMANAGE_TMP, SEMANAGE_USERS_EXTRA_LINKED); - if (access(path, F_OK) != 0) { - do_rebuild = 1; - goto rebuild; + do_rebuild = 1; + goto rebuild; + } } } @@ -1465,7 +1473,7 @@ rebuild: goto cleanup; path = semanage_path(SEMANAGE_TMP, SEMANAGE_SEUSERS_LINKED); - if (access(path, F_OK) == 0) { + if (stat(path, &sb) == 0) { retval = semanage_copy_file(path, semanage_path(SEMANAGE_TMP, SEMANAGE_STORE_SEUSERS), @@ -1473,12 +1481,18 @@ rebuild: if (retval < 0) goto cleanup; pseusers->dtable->drop_cache(pseusers->dbase); - } else { + } else if (errno == ENOENT) { + /* The file does not exist */ pseusers->dtable->clear(sh, pseusers->dbase); + } else { + ERR(sh, "Unable to access %s: %s\n", path, strerror(errno)); + goto cleanup; } + + path = semanage_path(SEMANAGE_TMP, SEMANAGE_USERS_EXTRA_LINKED); - if (access(path, F_OK) == 0) { + if (stat(path, &sb) == 0) { retval = semanage_copy_file(path, semanage_path(SEMANAGE_TMP, SEMANAGE_USERS_EXTRA), @@ -1486,8 +1500,12 @@ rebuild: if (retval < 0) goto cleanup; pusers_extra->dtable->drop_cache(pusers_extra->dbase); - } else { + } else if (errno == ENOENT) { + /* The file does not exist */ pusers_extra->dtable->clear(sh, pusers_extra->dbase); + } else { + ERR(sh, "Unable to access %s: %s\n", path, strerror(errno)); + goto cleanup; } } @@ -1817,6 +1835,7 @@ static int semanage_direct_extract(semanage_handle_t * sh, ssize_t _data_len; char *_data; int compressed; + struct stat sb; /* get path of module */ rc = semanage_module_get_path( @@ -1829,8 +1848,8 @@ static int semanage_direct_extract(semanage_handle_t * sh, goto cleanup; } - if (access(module_path, F_OK) != 0) { - ERR(sh, "Module does not exist: %s", module_path); + if (stat(module_path, &sb) != 0) { + ERR(sh, "Unable to access %s: %s\n", module_path, strerror(errno)); rc = -1; goto cleanup; } @@ -1859,7 +1878,12 @@ static int semanage_direct_extract(semanage_handle_t * sh, goto cleanup; } - if (extract_cil == 1 && strcmp(_modinfo->lang_ext, "cil") && access(input_file, F_OK) != 0) { + if (extract_cil == 1 && strcmp(_modinfo->lang_ext, "cil") && stat(input_file, &sb) != 0) { + if (errno != ENOENT) { + ERR(sh, "Unable to access %s: %s\n", input_file, strerror(errno)); + goto cleanup; + } + rc = semanage_compile_module(sh, _modinfo); if (rc < 0) { goto cleanup; @@ -2004,6 +2028,12 @@ static int semanage_direct_get_enabled(semanage_handle_t *sh, } if (stat(path, &sb) < 0) { + if (errno != ENOENT) { + ERR(sh, "Unable to access %s: %s\n", path, strerror(errno)); + status = -1; + goto cleanup; + } + *enabled = 1; } else { @@ -2330,6 +2360,12 @@ static int semanage_direct_get_module_info(semanage_handle_t *sh, /* set enabled/disabled status */ if (stat(fn, &sb) < 0) { + if (errno != ENOENT) { + ERR(sh, "Unable to access %s: %s\n", fn, strerror(errno)); + status = -1; + goto cleanup; + } + ret = semanage_module_info_set_enabled(sh, *modinfo, 1); if (ret != 0) { status = -1; @@ -2738,6 +2774,7 @@ static int semanage_direct_install_info(semanage_handle_t *sh, int status = 0; int ret = 0; int type; + struct stat sb; char path[PATH_MAX]; mode_t mask = umask(0077); @@ -2838,7 +2875,7 @@ static int semanage_direct_install_info(semanage_handle_t *sh, goto cleanup; } - if (access(path, F_OK) == 0) { + if (stat(path, &sb) == 0) { ret = unlink(path); if (ret != 0) { ERR(sh, "Error while removing cached CIL file %s: %s", path, strerror(errno)); diff --git a/libsemanage/src/semanage_store.c b/libsemanage/src/semanage_store.c index 4bd1d651..10f8b306 100644 --- a/libsemanage/src/semanage_store.c +++ b/libsemanage/src/semanage_store.c @@ -514,6 +514,7 @@ char *semanage_conf_path(void) { char *semanage_conf = NULL; int len; + struct stat sb; len = strlen(semanage_root()) + strlen(selinux_path()) + strlen(SEMANAGE_CONF_FILE); semanage_conf = calloc(len + 1, sizeof(char)); @@ -522,7 +523,12 @@ char *semanage_conf_path(void) snprintf(semanage_conf, len + 1, "%s%s%s", semanage_root(), selinux_path(), SEMANAGE_CONF_FILE); - if (access(semanage_conf, R_OK) != 0) { + if (stat(semanage_conf, &sb) != 0) { + if (errno != ENOENT) { + /* semanage_conf exists but can't be accessed */ + return NULL; + } + snprintf(semanage_conf, len + 1, "%s%s", selinux_path(), SEMANAGE_CONF_FILE); } @@ -1508,8 +1514,14 @@ int semanage_split_fc(semanage_handle_t * sh) static int sefcontext_compile(semanage_handle_t * sh, const char *path) { int r; + struct stat sb; + + if (stat(path, &sb) < 0) { + if (errno != ENOENT) { + ERR(sh, "Unable to access %s: %s\n", path, strerror(errno)); + return -1; + } - if (access(path, F_OK) != 0) { return 0; } -- 2.14.3
