From patchwork Wed Jun 7 12:39:49 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxim Mikityanskiy X-Patchwork-Id: 690728 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 28A85C77B7A for ; Wed, 7 Jun 2023 12:41:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235617AbjFGMlJ (ORCPT ); Wed, 7 Jun 2023 08:41:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50246 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240355AbjFGMlF (ORCPT ); Wed, 7 Jun 2023 08:41:05 -0400 Received: from mail-ed1-x531.google.com (mail-ed1-x531.google.com [IPv6:2a00:1450:4864:20::531]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAD751BF5; Wed, 7 Jun 2023 05:40:37 -0700 (PDT) Received: by mail-ed1-x531.google.com with SMTP id 4fb4d7f45d1cf-516a0546230so551959a12.3; Wed, 07 Jun 2023 05:40:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1686141596; x=1688733596; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=hQn0uFJCpJmXCmOjjUjAo32a6wELEyxybu3QCQdKk+w=; b=bv6hmv2YOewAE7kjkWMOVJmTObd3L/faqOwrXginYUwm21qYyRIJzStoFTUNs2YgoE fcRDRzyCaC65CDT85Sl1sYiKHSeFvrmswE/ODpQwPGQIe952ATGdAgHgSWOZKQhGU+ir GdIAKR4MqubC9TZy2Mt2UJTOJtBluVXG02bpZBQ318vY//DKo1BDvpw4Pa8m+ryCoAoj OQTyvomDkiRwboC4u3m8hbiNlPrWgl2cJArQwEeX+VMlxVqMD27jLJL+39hJpw5/3xCb aqjTfTQHRJYzx5eAlyKHF//hV0lLl/bG8ojCZ5B5LZvnvOktb1sE58njba3Xafan0e+i Nftw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686141596; x=1688733596; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=hQn0uFJCpJmXCmOjjUjAo32a6wELEyxybu3QCQdKk+w=; b=TiyUxO1nCoCutKb1htyd5aA+rc0qNl5zZyrIG06+Ep5Z5O8QZCutKkt4/Q+bdATJEW IuG85xYJWoi3gryEZLSqSsC0iYDo+zsx94hEfyvqoge0fP3ALmp4SsnDg43F2JQWlbOi 1OsLf3Sub7cs0hH0GV7HrOYO6T2/6G107p/4lWnAdsTauEWytMkYOffIj6dki+jfv4ki VJ8ywcaXtcgEX6EtfOnXybUGq9b8gm6QX80Csp5tVJ44IMkVmuRnf/RmX3SSnkuwoIWg 3/n0CQlSnMIczSt2gazp5oj7OFCczmCw8MrIIjinVcmIqCNRShzVKwmdEZ8SBhF1Wrmh 6z3w== X-Gm-Message-State: AC+VfDziyAt3QlqvVOGntgpfcktJl0DIVUajETtL3Wu+c8ItDYePAUp7 wn5jljsdvXO8NQl3XNo+NsOiG4U8ZpC6jnVDNLY= X-Google-Smtp-Source: ACHHUZ5Eh44eDjG3RkZNH5AkQmsbiHi9keicnz4mxbPsfBxR7ahInzXb0pw3Ji16qhGi48b7TAM7Zg== X-Received: by 2002:aa7:c1c4:0:b0:514:a452:3f5 with SMTP id d4-20020aa7c1c4000000b00514a45203f5mr3944373edp.32.1686141595779; Wed, 07 Jun 2023 05:39:55 -0700 (PDT) Received: from localhost (tor-exit-48.for-privacy.net. [185.220.101.48]) by smtp.gmail.com with ESMTPSA id w8-20020aa7dcc8000000b00514a6d05de9sm6126356edu.88.2023.06.07.05.39.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 07 Jun 2023 05:39:55 -0700 (PDT) From: Maxim Mikityanskiy To: bpf@vger.kernel.org Cc: netdev@vger.kernel.org, linux-kselftest@vger.kernel.org, Daniel Borkmann , John Fastabend , Alexei Starovoitov , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Maxim Mikityanskiy , Song Liu , Yonghong Song , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Mykola Lysenko , Shuah Khan , "David S. Miller" , Jakub Kicinski , Jesper Dangaard Brouer Subject: [PATCH bpf v4 0/2] Fix verifier id tracking of scalars on spill Date: Wed, 7 Jun 2023 15:39:49 +0300 Message-Id: <20230607123951.558971-1-maxtram95@gmail.com> X-Mailer: git-send-email 2.40.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org From: Maxim Mikityanskiy See the details in the commit message (TL/DR: under CAP_BPF, the verifier can incorrectly conclude that a scalar is zero while in fact it can be crafted to a predefined number.) v1 and v2 were sent off-list. v2 changes: Added more tests, migrated them to inline asm, started using bpf_get_prandom_u32, switched to a more bulletproof dead branch check and modified the failing spill test scenarios so that an unauthorized access attempt is performed in both branches. v3 changes: Dropped an improvement not necessary for the fix, changed the Fixes tag. v4 changes: Dropped supposedly redundant tests, kept the ones that result in different verifier verdicts. Dropped the variable that is not yet useful in this patch. Rephrased the commit message with Daniel's suggestions. Maxim Mikityanskiy (2): bpf: Fix verifier id tracking of scalars on spill selftests/bpf: Add test cases to assert proper ID tracking on spill kernel/bpf/verifier.c | 3 + .../selftests/bpf/progs/verifier_spill_fill.c | 79 +++++++++++++++++++ 2 files changed, 82 insertions(+)