Let's drop the caching of the setgroups /proc field for now. While there's a
strict regime in place when it changes states, let's better not cache it since
we cannot really be sure we follow that regime correctly.
More importantly however, this is not in performance sensitive code, and
there's no indication the cache is really beneficial, hence let's drop the
caching and make things a bit simpler.
Also, while we are at it, rework the error handling a bit, and always return
negative errno-style error codes, following our usual coding style. This has
the benefit that we can sensible hanld read_one_line_file() errors, without
having to updat errno explicitly.
if (setresgid(gid, gid, gid) < 0)
return log_error_errno(errno, "Failed to change group ID: %m");
if (setresgid(gid, gid, gid) < 0)
return log_error_errno(errno, "Failed to change group ID: %m");
- if (maybe_setgroups(0, NULL) < 0)
- return log_error_errno(errno, "Failed to drop auxiliary groups list: %m");
+ r = maybe_setgroups(0, NULL);
+ if (r < 0)
+ return log_error_errno(r, "Failed to drop auxiliary groups list: %m");
/* Ensure we keep the permitted caps across the setresuid() */
if (prctl(PR_SET_KEEPCAPS, 1) < 0)
/* Ensure we keep the permitted caps across the setresuid() */
if (prctl(PR_SET_KEEPCAPS, 1) < 0)
}
int reset_uid_gid(void) {
}
int reset_uid_gid(void) {
- if (maybe_setgroups(0, NULL) < 0)
- return -errno;
+ r = maybe_setgroups(0, NULL);
+ if (r < 0)
+ return r;
if (setresgid(0, 0, 0) < 0)
return -errno;
if (setresgid(0, 0, 0) < 0)
return -errno;
}
int maybe_setgroups(size_t size, const gid_t *list) {
}
int maybe_setgroups(size_t size, const gid_t *list) {
- static int cached_can_setgroups = -1;
- /* check if setgroups is allowed before we try to drop all the auxiliary groups */
- if (size == 0) {
- if (cached_can_setgroups < 0) {
- _cleanup_free_ char *setgroups_content = NULL;
- int r = read_one_line_file("/proc/self/setgroups", &setgroups_content);
- if (r < 0 && errno != ENOENT)
- return r;
- if (r < 0) {
- /* old kernels don't have /proc/self/setgroups, so assume we can use setgroups */
- cached_can_setgroups = true;
- } else {
- cached_can_setgroups = streq(setgroups_content, "allow");
- if (!cached_can_setgroups)
- log_debug("skip setgroups, /proc/self/setgroups is set to 'deny'");
- }
- }
- if (!cached_can_setgroups)
+ int r;
+
+ /* Check if setgroups is allowed before we try to drop all the auxiliary groups */
+ if (size == 0) { /* Dropping all aux groups? */
+ _cleanup_free_ char *setgroups_content = NULL;
+ bool can_setgroups;
+
+ r = read_one_line_file("/proc/self/setgroups", &setgroups_content);
+ if (r == -ENOENT)
+ /* Old kernels don't have /proc/self/setgroups, so assume we can use setgroups */
+ can_setgroups = true;
+ else if (r < 0)
+ return r;
+ else
+ can_setgroups = streq(setgroups_content, "allow");
+
+ if (!can_setgroups) {
+ log_debug("Skipping setgroups(), /proc/self/setgroups is set to 'deny'");
- return setgroups(size, list);
+
+ if (setgroups(size, list) < 0)
+ return -errno;
+
+ return 0;
- if (maybe_setgroups(k, gids) < 0) {
+ r = maybe_setgroups(k, gids);
+ if (r < 0) {
* If this fails, ignore the error - but expect sd-pam threads
* to fail to exit normally */
* If this fails, ignore the error - but expect sd-pam threads
* to fail to exit normally */
- if (maybe_setgroups(0, NULL) < 0)
- log_warning_errno(errno, "Failed to setgroups() in sd-pam: %m");
+ r = maybe_setgroups(0, NULL);
+ if (r < 0)
+ log_warning_errno(r, "Failed to setgroups() in sd-pam: %m");
if (setresgid(gid, gid, gid) < 0)
log_warning_errno(errno, "Failed to setresgid() in sd-pam: %m");
if (setresuid(uid, uid, uid) < 0)
if (setresgid(gid, gid, gid) < 0)
log_warning_errno(errno, "Failed to setresgid() in sd-pam: %m");
if (setresuid(uid, uid, uid) < 0)