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=-13.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, 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 CE389C433E2 for ; Tue, 1 Sep 2020 15:44:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 97AEA206EB for ; Tue, 1 Sep 2020 15:44:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598975040; bh=TYTTdCegp15oLYrWq/F7PP5Ab8BnxcWk62tjoSVlprc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=u7i47xg/qfKi1DZhh763KKD9kOZIZ/Oo14PszAU0/ppGhRAYtsHjrf2XCL9E9vl+e 1AH32b66cWsff8v07aVpGzp7EXgIRXax2JbbimfYTYDXLD2jbDQpWWZ6eRctIfJibl gRCud38A6q+9vONdy/8atZx5WJYDJ4Tiyt/fGdno= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731725AbgIAPn5 (ORCPT ); Tue, 1 Sep 2020 11:43:57 -0400 Received: from mail.kernel.org ([198.145.29.99]:53378 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730616AbgIAPlW (ORCPT ); Tue, 1 Sep 2020 11:41:22 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 C46F1206EB; Tue, 1 Sep 2020 15:41:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1598974880; bh=TYTTdCegp15oLYrWq/F7PP5Ab8BnxcWk62tjoSVlprc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Bwd3Xi4C1KYyvuUCd8bkTFO/tHAXpuwCYnUnLvAwPn7f7pTK4Y2eyFWmDNCW53o8M Ot0iWMThnKLDfibJfaW39ldcpBtOcYPATRHDY7PPDCuMQv4NUGemJJJRJBukMR5WfY BNawrRqStVr5IysMrTjLPKQelGWLKHpYV+eNqvmo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jianlin Lv , Daniel Borkmann , Andrii Nakryiko , Sasha Levin Subject: [PATCH 5.8 126/255] selftests/bpf: Fix segmentation fault in test_progs Date: Tue, 1 Sep 2020 17:09:42 +0200 Message-Id: <20200901151006.765388854@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200901151000.800754757@linuxfoundation.org> References: <20200901151000.800754757@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: Jianlin Lv [ Upstream commit 0390c429dbed4068bd2cd8dded937d9a5ec24cd2 ] test_progs reports the segmentation fault as below: $ sudo ./test_progs -t mmap --verbose test_mmap:PASS:skel_open_and_load 0 nsec [...] test_mmap:PASS:adv_mmap1 0 nsec test_mmap:PASS:adv_mmap2 0 nsec test_mmap:PASS:adv_mmap3 0 nsec test_mmap:PASS:adv_mmap4 0 nsec Segmentation fault This issue was triggered because mmap() and munmap() used inconsistent length parameters; mmap() creates a new mapping of 3 * page_size, but the length parameter set in the subsequent re-map and munmap() functions is 4 * page_size; this leads to the destruction of the process space. To fix this issue, first create 4 pages of anonymous mapping, then do all the mmap() with MAP_FIXED. Another issue is that when unmap the second page fails, the length parameter to delete tmp1 mappings should be 4 * page_size. Signed-off-by: Jianlin Lv Signed-off-by: Daniel Borkmann Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200810153940.125508-1-Jianlin.Lv@arm.com Signed-off-by: Sasha Levin --- tools/testing/selftests/bpf/prog_tests/mmap.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/mmap.c b/tools/testing/selftests/bpf/prog_tests/mmap.c index 43d0b5578f461..9c3c5c0f068fb 100644 --- a/tools/testing/selftests/bpf/prog_tests/mmap.c +++ b/tools/testing/selftests/bpf/prog_tests/mmap.c @@ -21,7 +21,7 @@ void test_mmap(void) const long page_size = sysconf(_SC_PAGE_SIZE); int err, duration = 0, i, data_map_fd, data_map_id, tmp_fd, rdmap_fd; struct bpf_map *data_map, *bss_map; - void *bss_mmaped = NULL, *map_mmaped = NULL, *tmp1, *tmp2; + void *bss_mmaped = NULL, *map_mmaped = NULL, *tmp0, *tmp1, *tmp2; struct test_mmap__bss *bss_data; struct bpf_map_info map_info; __u32 map_info_sz = sizeof(map_info); @@ -183,16 +183,23 @@ void test_mmap(void) /* check some more advanced mmap() manipulations */ + tmp0 = mmap(NULL, 4 * page_size, PROT_READ, MAP_SHARED | MAP_ANONYMOUS, + -1, 0); + if (CHECK(tmp0 == MAP_FAILED, "adv_mmap0", "errno %d\n", errno)) + goto cleanup; + /* map all but last page: pages 1-3 mapped */ - tmp1 = mmap(NULL, 3 * page_size, PROT_READ, MAP_SHARED, + tmp1 = mmap(tmp0, 3 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED, data_map_fd, 0); - if (CHECK(tmp1 == MAP_FAILED, "adv_mmap1", "errno %d\n", errno)) + if (CHECK(tmp0 != tmp1, "adv_mmap1", "tmp0: %p, tmp1: %p\n", tmp0, tmp1)) { + munmap(tmp0, 4 * page_size); goto cleanup; + } /* unmap second page: pages 1, 3 mapped */ err = munmap(tmp1 + page_size, page_size); if (CHECK(err, "adv_mmap2", "errno %d\n", errno)) { - munmap(tmp1, map_sz); + munmap(tmp1, 4 * page_size); goto cleanup; } @@ -201,7 +208,7 @@ void test_mmap(void) MAP_SHARED | MAP_FIXED, data_map_fd, 0); if (CHECK(tmp2 == MAP_FAILED, "adv_mmap3", "errno %d\n", errno)) { munmap(tmp1, page_size); - munmap(tmp1 + 2*page_size, page_size); + munmap(tmp1 + 2*page_size, 2 * page_size); goto cleanup; } CHECK(tmp1 + page_size != tmp2, "adv_mmap4", @@ -211,7 +218,7 @@ void test_mmap(void) tmp2 = mmap(tmp1, 4 * page_size, PROT_READ, MAP_SHARED | MAP_FIXED, data_map_fd, 0); if (CHECK(tmp2 == MAP_FAILED, "adv_mmap5", "errno %d\n", errno)) { - munmap(tmp1, 3 * page_size); /* unmap page 1 */ + munmap(tmp1, 4 * page_size); /* unmap page 1 */ goto cleanup; } CHECK(tmp1 != tmp2, "adv_mmap6", "tmp1: %p, tmp2: %p\n", tmp1, tmp2); -- 2.25.1