-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
/***
This file is part of systemd.
#ifdef HAVE_SELINUX
-#include <stdio.h>
-#include <string.h>
#include <errno.h>
-#include <limits.h>
-#include <selinux/selinux.h>
#include <selinux/avc.h>
-#include <sys/socket.h>
+#include <selinux/selinux.h>
+#include <stdio.h>
#ifdef HAVE_AUDIT
#include <libaudit.h>
#endif
#include "sd-bus.h"
+
+#include "alloc-util.h"
+#include "audit-fd.h"
#include "bus-util.h"
-#include "util.h"
#include "log.h"
-#include "audit.h"
+#include "path-util.h"
#include "selinux-util.h"
-#include "audit-fd.h"
+#include "stdio-util.h"
#include "strv.h"
+#include "util.h"
static bool initialized = false;
const struct audit_info *audit = auditdata;
uid_t uid = 0, login_uid = 0;
gid_t gid = 0;
- char login_uid_buf[DECIMAL_STR_MAX(uid_t)] = "n/a";
- char uid_buf[DECIMAL_STR_MAX(uid_t)] = "n/a";
- char gid_buf[DECIMAL_STR_MAX(gid_t)] = "n/a";
+ char login_uid_buf[DECIMAL_STR_MAX(uid_t) + 1] = "n/a";
+ char uid_buf[DECIMAL_STR_MAX(uid_t) + 1] = "n/a";
+ char gid_buf[DECIMAL_STR_MAX(gid_t) + 1] = "n/a";
if (sd_bus_creds_get_audit_login_uid(audit->creds, &login_uid) >= 0)
- snprintf(login_uid_buf, sizeof(login_uid_buf), UID_FMT, login_uid);
- if (sd_bus_creds_get_uid(audit->creds, &uid) >= 0)
- snprintf(uid_buf, sizeof(uid_buf), UID_FMT, uid);
- if (sd_bus_creds_get_gid(audit->creds, &gid) >= 0)
- snprintf(gid_buf, sizeof(gid_buf), GID_FMT, gid);
+ xsprintf(login_uid_buf, UID_FMT, login_uid);
+ if (sd_bus_creds_get_euid(audit->creds, &uid) >= 0)
+ xsprintf(uid_buf, UID_FMT, uid);
+ if (sd_bus_creds_get_egid(audit->creds, &gid) >= 0)
+ xsprintf(gid_buf, GID_FMT, gid);
snprintf(msgbuf, msgbufsize,
"auid=%s uid=%s gid=%s%s%s%s%s%s%s",
audit->path ? " path=\"" : "", strempty(audit->path), audit->path ? "\"" : "",
audit->cmdline ? " cmdline=\"" : "", strempty(audit->cmdline), audit->cmdline ? "\"" : "");
- msgbuf[msgbufsize-1] = 0;
-
return 0;
}
+static int callback_type_to_priority(int type) {
+ switch(type) {
+
+ case SELINUX_ERROR:
+ return LOG_ERR;
+
+ case SELINUX_WARNING:
+ return LOG_WARNING;
+
+ case SELINUX_INFO:
+ return LOG_INFO;
+
+ case SELINUX_AVC:
+ default:
+ return LOG_NOTICE;
+ }
+}
+
/*
- Any time an access gets denied this callback will be called
- code copied from dbus. If audit is turned on the messages will go as
- user_avc's into the /var/log/audit/audit.log, otherwise they will be
- sent to syslog.
+ libselinux uses this callback when access gets denied or other
+ events happen. If audit is turned on, messages will be reported
+ using audit netlink, otherwise they will be logged using the usual
+ channels.
+
+ Code copied from dbus and modified.
*/
_printf_(2, 3) static int log_callback(int type, const char *fmt, ...) {
va_list ap;
#ifdef HAVE_AUDIT
- if (get_audit_fd() >= 0) {
+ int fd;
+
+ fd = get_audit_fd();
+
+ if (fd >= 0) {
_cleanup_free_ char *buf = NULL;
int r;
va_end(ap);
if (r >= 0) {
- audit_log_user_avc_message(get_audit_fd(), AUDIT_USER_AVC, buf, NULL, NULL, NULL, 0);
+ audit_log_user_avc_message(fd, AUDIT_USER_AVC, buf, NULL, NULL, NULL, 0);
return 0;
}
}
#endif
va_start(ap, fmt);
- log_internalv(LOG_AUTH | LOG_INFO, 0, __FILE__, __LINE__, __FUNCTION__, fmt, ap);
+ log_internalv(LOG_AUTH | callback_type_to_priority(type), 0, __FILE__, __LINE__, __FUNCTION__, fmt, ap);
va_end(ap);
return 0;
}
-/*
- Function must be called once to initialize the SELinux AVC environment.
- Sets up callbacks.
- If you want to cleanup memory you should need to call selinux_access_finish.
-*/
-static int access_init(void) {
- int r = 0;
-
- if (avc_open(NULL, 0)) {
- log_error("avc_open() failed: %m");
- return -errno;
- }
-
- selinux_set_callback(SELINUX_CB_AUDIT, (union selinux_callback) audit_callback);
- selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) log_callback);
+static int access_init(sd_bus_error *error) {
- if (security_getenforce() < 0){
- r = -errno;
- avc_destroy();
- }
-
- return r;
-}
-
-static int mac_selinux_access_init(sd_bus_error *error) {
- int r;
+ if (!mac_selinux_use())
+ return 0;
if (initialized)
- return 0;
+ return 1;
- if (!mac_selinux_use())
- return 0;
+ if (avc_open(NULL, 0) != 0) {
+ int enforce, saved_errno = errno;
- r = access_init();
- if (r < 0)
- return sd_bus_error_set(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to initialize SELinux.");
+ enforce = security_getenforce();
+ log_full_errno(enforce != 0 ? LOG_ERR : LOG_WARNING, saved_errno, "Failed to open the SELinux AVC: %m");
- initialized = true;
- return 0;
-}
-#endif
+ /* If enforcement isn't on, then let's suppress this
+ * error, and just don't do any AVC checks. The
+ * warning we printed is hence all the admin will
+ * see. */
+ if (enforce == 0)
+ return 0;
-void mac_selinux_access_free(void) {
+ /* Return an access denied error, if we couldn't load
+ * the AVC but enforcing mode was on, or we couldn't
+ * determine whether it is one. */
+ return sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to open the SELinux AVC: %s", strerror(saved_errno));
+ }
-#ifdef HAVE_SELINUX
- if (!initialized)
- return;
+ selinux_set_callback(SELINUX_CB_AUDIT, (union selinux_callback) audit_callback);
+ selinux_set_callback(SELINUX_CB_LOG, (union selinux_callback) log_callback);
- avc_destroy();
- initialized = false;
-#endif
+ initialized = true;
+ return 1;
}
/*
const char *permission,
sd_bus_error *error) {
-#ifdef HAVE_SELINUX
- _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+ _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
const char *tclass = NULL, *scon = NULL;
struct audit_info audit_info = {};
_cleanup_free_ char *cl = NULL;
assert(permission);
assert(error);
- if (!mac_selinux_use())
- return 0;
-
- r = mac_selinux_access_init(error);
- if (r < 0)
+ r = access_init(error);
+ if (r <= 0)
return r;
r = sd_bus_query_sender_creds(
message,
- SD_BUS_CREDS_PID|SD_BUS_CREDS_UID|SD_BUS_CREDS_GID|
+ SD_BUS_CREDS_PID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_EGID|
SD_BUS_CREDS_CMDLINE|SD_BUS_CREDS_AUDIT_LOGIN_UID|
SD_BUS_CREDS_SELINUX_CONTEXT|
SD_BUS_CREDS_AUGMENT /* get more bits from /proc */,
if (r < 0)
goto finish;
+ /* The SELinux context is something we really should have
+ * gotten directly from the message or sender, and not be an
+ * augmented field. If it was augmented we cannot use it for
+ * authorization, since this is racy and vulnerable. Let's add
+ * an extra check, just in case, even though this really
+ * shouldn't be possible. */
+ assert_return((sd_bus_creds_get_augmented_mask(creds) & SD_BUS_CREDS_SELINUX_CONTEXT) == 0, -EPERM);
+
r = sd_bus_creds_get_selinux_context(creds, &scon);
if (r < 0)
goto finish;
if (path) {
/* Get the file context of the unit file */
- r = getfilecon(path, &fcon);
+ r = getfilecon_raw(path, &fcon);
if (r < 0) {
r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to get file context on %s.", path);
goto finish;
tclass = "service";
} else {
- r = getcon(&fcon);
+ r = getcon_raw(&fcon);
if (r < 0) {
r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "Failed to get current context.");
goto finish;
audit_info.path = path;
audit_info.cmdline = cl;
- r = selinux_check_access((security_context_t) scon, fcon, tclass, permission, &audit_info);
+ r = selinux_check_access(scon, fcon, tclass, permission, &audit_info);
if (r < 0)
r = sd_bus_error_setf(error, SD_BUS_ERROR_ACCESS_DENIED, "SELinux policy denies access.");
}
return r;
+}
+
#else
+
+int mac_selinux_generic_access_check(
+ sd_bus_message *message,
+ const char *path,
+ const char *permission,
+ sd_bus_error *error) {
+
return 0;
-#endif
}
-int mac_selinux_unit_access_check_strv(char **units,
- sd_bus_message *message,
- Manager *m,
- const char *permission,
- sd_bus_error *error) {
-#ifdef HAVE_SELINUX
- char **i;
- Unit *u;
- int r;
-
- STRV_FOREACH(i, units) {
- u = manager_get_unit(m, *i);
- if (u) {
- r = mac_selinux_unit_access_check(u, message, permission, error);
- if (r < 0)
- return r;
- }
- }
#endif
- return 0;
-}
projects / thirdparty / systemd.git / blobdiff