@@ -549,6 +549,14 @@ static ssize_t cgroup_release_agent_write(struct kernfs_open_file *of,
BUILD_BUG_ON(sizeof(cgrp->root->release_agent_path) < PATH_MAX);
+ /*
+ * Release agent gets called with all capabilities,
+ * require capabilities to set release agent.
+ */
+ if ((of->file->f_cred->user_ns != &init_user_ns) ||
+ !capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
cgrp = cgroup_kn_lock_live(of->kn, false);
if (!cgrp)
return -ENODEV;
@@ -961,6 +969,12 @@ int cgroup1_parse_param(struct fs_context *fc, struct fs_parameter *param)
/* Specifying two release agents is forbidden */
if (ctx->release_agent)
return cg_invalf(fc, "cgroup1: release_agent respecified");
+ /*
+ * Release agent gets called with all capabilities,
+ * require capabilities to set release agent.
+ */
+ if ((fc->user_ns != &init_user_ns) || !capable(CAP_SYS_ADMIN))
+ return cg_invalf(fc, "cgroup1: Setting release_agent not allowed");
ctx->release_agent = param->string;
param->string = NULL;
break;