From patchwork Wed Apr 3 22:15:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrey Ignatov X-Patchwork-Id: 1076500 Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=fb.com Authentication-Results: ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=fb.com header.i=@fb.com header.b="e9grS8sZ"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 44ZL4V6KChz9sSW for ; Thu, 4 Apr 2019 09:15:38 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726565AbfDCWPh (ORCPT ); Wed, 3 Apr 2019 18:15:37 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:34808 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726218AbfDCWPe (ORCPT ); Wed, 3 Apr 2019 18:15:34 -0400 Received: from pps.filterd (m0089730.ppops.net [127.0.0.1]) by m0089730.ppops.net (8.16.0.27/8.16.0.27) with SMTP id x33M9VPj002586 for ; Wed, 3 Apr 2019 15:15:33 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : mime-version : content-type; s=facebook; bh=dR3KUelt3x83uxQIry8IiqWG9wUnAlmBrna/MNMf0Zs=; b=e9grS8sZ3UnC5na/MaV3XYVGIdR4yhjJyZU8h5coviYxvBKcfhmdP/QtzOvq9h42es/U djX1YN9nZwg+RC8QTXkhLzCizeFdDKPPIX40kApMbo/9T76tZjeArfZHQPiIQH82gRAN xbz+16TXy+SlD3zMdAt5kB+h/7aMWMjK3vo= Received: from mail.thefacebook.com ([199.201.64.23]) by m0089730.ppops.net with ESMTP id 2rn0cb99v3-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT) for ; Wed, 03 Apr 2019 15:15:33 -0700 Received: from mx-out.facebook.com (2620:10d:c081:10::13) by mail.thefacebook.com (2620:10d:c081:35::130) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA) id 15.1.1713.5; Wed, 3 Apr 2019 15:15:31 -0700 Received: by dev082.prn2.facebook.com (Postfix, from userid 572249) id 5F51C3702951; Wed, 3 Apr 2019 15:15:31 -0700 (PDT) Smtp-Origin-Hostprefix: dev From: Andrey Ignatov Smtp-Origin-Hostname: dev082.prn2.facebook.com To: CC: Andrey Ignatov , , , Smtp-Origin-Cluster: prn2c23 Subject: [PATCH v2 bpf-next 0/5] bpf: Fix indirect var_off stack access support Date: Wed, 3 Apr 2019 15:15:19 -0700 Message-ID: X-Mailer: git-send-email 2.17.1 X-FB-Internal: Safe MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-04-03_13:, , signatures=0 X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org v1->v2: - rely on meta = NULL to reject var_off stack access to uninit buffer. This patch set is a follow-up for discussion [1]. It fixes variable offset stack access handling for raw and unprivileged mode, rejecting both of them. Patch 1 handles raw (uninitialized) mode. Patch 2 adds test for raw mode. Patch 3 handles unprivileged mode. Patch 4 adds test for unprivileged mode. Patch 5 is a minor fix in verbose log. Unprivileged mode is an interesting case since one (and only?) way to come up with variable offset is to use pointer arithmetics. Though pointer arithmetics is already prohibited for unprivileged mode. I'm not sure if it's enough though and it seems like a good idea to still reject variable offset for unpriv in check_stack_boundary(). Please see patches 3 and 4 for more details on this. [1] https://marc.info/?l=linux-netdev&m=155419526427742&w=2 Andrey Ignatov (5): bpf: Reject indirect var_off stack access in raw mode selftests/bpf: Test indirect var_off stack access in raw mode bpf: Reject indirect var_off stack access in unpriv mode selftests/bpf: Test indirect var_off stack access in unpriv mode bpf: Add missed newline in verifier verbose log kernel/bpf/verifier.c | 27 +++++++++- .../testing/selftests/bpf/verifier/var_off.c | 54 +++++++++++++++++++ 2 files changed, 80 insertions(+), 1 deletion(-)