From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F38BC43382 for ; Thu, 27 Sep 2018 09:11:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3F06720836 for ; Thu, 27 Sep 2018 09:11:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3F06720836 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728522AbeI0P2k (ORCPT ); Thu, 27 Sep 2018 11:28:40 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:55250 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727131AbeI0P2j (ORCPT ); Thu, 27 Sep 2018 11:28:39 -0400 Received: from localhost (ip-213-127-77-73.ip.prioritytelecom.net [213.127.77.73]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 6654A111D; Thu, 27 Sep 2018 09:11:23 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jann Horn , Daniel Borkmann , Alexei Starovoitov Subject: [PATCH 4.18 54/88] bpf/verifier: disallow pointer subtraction Date: Thu, 27 Sep 2018 11:03:35 +0200 Message-Id: <20180927090307.374675294@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20180927090300.631426620@linuxfoundation.org> References: <20180927090300.631426620@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alexei Starovoitov commit dd066823db2ac4e22f721ec85190817b58059a54 upstream. Subtraction of pointers was accidentally allowed for unpriv programs by commit 82abbf8d2fc4. Revert that part of commit. Fixes: 82abbf8d2fc4 ("bpf: do not allow root to mangle valid pointers") Reported-by: Jann Horn Acked-by: Daniel Borkmann Signed-off-by: Alexei Starovoitov Signed-off-by: Daniel Borkmann Signed-off-by: Greg Kroah-Hartman --- kernel/bpf/verifier.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -3132,7 +3132,7 @@ static int adjust_reg_min_max_vals(struc * an arbitrary scalar. Disallow all math except * pointer subtraction */ - if (opcode == BPF_SUB){ + if (opcode == BPF_SUB && env->allow_ptr_leaks) { mark_reg_unknown(env, regs, insn->dst_reg); return 0; }