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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 94296C5518F for ; Wed, 22 Apr 2020 10:28:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6B15C20857 for ; Wed, 22 Apr 2020 10:28:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587551282; bh=FQ8uavis3YI3bIVKci40KEZIaz+QKDXjqwdyCDx3XZw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=T80SQz68oW1ryDz7vFsYREUYHA+pSNqv1QnYPFFuWhZPA3swoe077GR8MLqCjs2Nj huC0ZXhK8MOyVQCcFtVegrzRSDO+hM1N+375JmMQ3OgaVtsTr9XZEvDC6HfNT9ZZTK 5Wfs4I56PpV+PL5FLd3wWECg3Sk9vf8YuIDQAx0Q= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730980AbgDVK2B (ORCPT ); Wed, 22 Apr 2020 06:28:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:37160 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730962AbgDVK14 (ORCPT ); Wed, 22 Apr 2020 06:27:56 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id CD57F2071E; Wed, 22 Apr 2020 10:27:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587551276; bh=FQ8uavis3YI3bIVKci40KEZIaz+QKDXjqwdyCDx3XZw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GTRSnE3jCUoCBewhvU6Nxsv5UnokIf1sCYDn83M7eWDafAlVZu6Kocun+7qOI73eV L8TfpjCQu34U+kfCSFv5PgRMw5unZv39LJ7oEVxcPT5CWxinD0AWyiA0ClfVymmO1u kH4ty/kQFb2AhMMZFVDnU78x8Y2NCwTkEIut7W/g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, John Fastabend , Alexei Starovoitov , Daniel Borkmann Subject: [PATCH 5.6 165/166] bpf: Test_progs, add test to catch retval refine error handling Date: Wed, 22 Apr 2020 11:58:12 +0200 Message-Id: <20200422095106.068884565@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200422095047.669225321@linuxfoundation.org> References: <20200422095047.669225321@linuxfoundation.org> User-Agent: quilt/0.66 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 From: John Fastabend commit d2db08c7a14e0b5eed6132baf258b80622e041a9 upstream. Before this series the verifier would clamp return bounds of bpf_get_stack() to [0, X] and this led the verifier to believe that a JMP_JSLT 0 would be false and so would prune that path. The result is anything hidden behind that JSLT would be unverified. Add a test to catch this case by hiding an goto pc-1 behind the check which will cause an infinite loop if not rejected. Signed-off-by: John Fastabend Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/158560423908.10843.11783152347709008373.stgit@john-Precision-5820-Tower Signed-off-by: Daniel Borkmann Signed-off-by: Greg Kroah-Hartman --- tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c | 5 ++ tools/testing/selftests/bpf/progs/test_get_stack_rawtp_err.c | 26 +++++++++++ 2 files changed, 31 insertions(+) --- a/tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c +++ b/tools/testing/selftests/bpf/prog_tests/get_stack_raw_tp.c @@ -82,6 +82,7 @@ static void get_stack_print_output(void void test_get_stack_raw_tp(void) { const char *file = "./test_get_stack_rawtp.o"; + const char *file_err = "./test_get_stack_rawtp_err.o"; const char *prog_name = "raw_tracepoint/sys_enter"; int i, err, prog_fd, exp_cnt = MAX_CNT_RAWTP; struct perf_buffer_opts pb_opts = {}; @@ -93,6 +94,10 @@ void test_get_stack_raw_tp(void) struct bpf_map *map; cpu_set_t cpu_set; + err = bpf_prog_load(file_err, BPF_PROG_TYPE_RAW_TRACEPOINT, &obj, &prog_fd); + if (CHECK(err >= 0, "prog_load raw tp", "err %d errno %d\n", err, errno)) + return; + err = bpf_prog_load(file, BPF_PROG_TYPE_RAW_TRACEPOINT, &obj, &prog_fd); if (CHECK(err, "prog_load raw tp", "err %d errno %d\n", err, errno)) return; --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_get_stack_rawtp_err.c @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +#define MAX_STACK_RAWTP 10 + +SEC("raw_tracepoint/sys_enter") +int bpf_prog2(void *ctx) +{ + __u64 stack[MAX_STACK_RAWTP]; + int error; + + /* set all the flags which should return -EINVAL */ + error = bpf_get_stack(ctx, stack, 0, -1); + if (error < 0) + goto loop; + + return error; +loop: + while (1) { + error++; + } +} + +char _license[] SEC("license") = "GPL";