GHSA-6jcq-6546-qrrw: PraisonAI SandlockSandbox falls back to unrestricted subprocess execution when Landlock is unavailable

Summary praisonai.sandbox.SandlockSandbox is documented and implemented as the kernel-enforced sandbox backend for untrusted code. Its SandboxConfig.native() path lets callers configure allowed filesystem paths and network=False. On systems where the optional sandlock module imports but reports that Landlock is unavailable, SandlockSandbox.execute() and run_command() do not fail closed. They silently fall back to SubprocessSandbox(self.config). That fallback keeps the same high-level native policy object but does not enforce the native filesystem or network boundary during code execution. A sandboxed payload can read files outside the configured allowed path and open network connections despite network=False. Technical Details SandboxConfig.native() creates a restricted native policy and records caller-provided writable paths plus the requested network posture: return cls( sandbox_type="native", working_dir=os.getcwd(), security_policy=SecurityPolicy( allow_network=network, allow_file_write=True, allow_subprocess=True, allowed_paths=resolved_paths, ), metadata={"writable_paths": resolved_paths, "network": network}, ) SandlockSandbox builds the intended kernel policy with Landlock-backed filesystem allowlisting and network denial: policy = Policy( fs_readable=allowed_read_paths, fs_writable=allowed_write_paths, net_allow_hosts=[] if not limits.network_enabled else None, max_memory=f"{limits.memory_mb}M", max_processes=limits.max_processes, max_open_files=limits.max_open_files, ) However, both execution paths fail open when Sandlock is unavailable: if not self.is_available: logger.warning("Sandlock not available, falling back to subprocess") from .subprocess import SubprocessSandbox fallback = SubprocessSandbox(self.config) return await fallback.execute(code, language, limits, env, working_dir) SubprocessSandbox.execute() writes the code to a temp file and runs python with a minimal environment and POSIX rlimits. It does not install a filesystem sandbox, ne