Merge pull request #25509 from enr0n/oomd-unpriv-container-fix

Fix `oomd_fetch_cgroup_oom_preference()` for unprivileged LXD containers

src/oom/oomd-util.c

@@ -164,7 +164,7 @@ int oomd_fetch_cgroup_oom_preference(OomdCGroupContext *ctx, const char *prefix)
         if (r < 0)
                 return log_debug_errno(r, "Failed to get owner/group from %s: %m", ctx->path);
 
-        if (uid == prefix_uid) {
+        if (uid == prefix_uid || uid == 0) {
                 /* Ignore most errors when reading the xattr since it is usually unset and cgroup xattrs are only used
                  * as an optional feature of systemd-oomd (and the system might not even support them). */
                 r = cg_get_xattr_bool(SYSTEMD_CGROUP_CONTROLLER, ctx->path, "user.oomd_avoid");

src/oom/test-oomd-util.c

@@ -475,9 +475,9 @@ static void test_oomd_fetch_cgroup_oom_preference(void) {
 
         /* Assert that avoid/omit are not set if the cgroup and prefix are not
          * owned by the same user.*/
-        if (test_xattrs && !empty_or_root(ctx->path)) {
+        if (test_xattrs && !empty_or_root(cgroup)) {
                 ctx = oomd_cgroup_context_free(ctx);
-                assert_se(cg_set_access(SYSTEMD_CGROUP_CONTROLLER, cgroup, 65534, 0) >= 0);
+                assert_se(cg_set_access(SYSTEMD_CGROUP_CONTROLLER, cgroup, 61183, 0) >= 0);
                 assert_se(oomd_cgroup_context_acquire(cgroup, &ctx) == 0);
 
                 assert_se(oomd_fetch_cgroup_oom_preference(ctx, NULL) == 0);