From patchwork Tue Feb 1 01:16:37 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 539977 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 900ABC433F5 for ; Tue, 1 Feb 2022 01:16:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231722AbiBABQl (ORCPT ); Mon, 31 Jan 2022 20:16:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45276 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231742AbiBABQk (ORCPT ); Mon, 31 Jan 2022 20:16:40 -0500 Received: from mail-pg1-x535.google.com (mail-pg1-x535.google.com [IPv6:2607:f8b0:4864:20::535]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BFC4C06173B for ; Mon, 31 Jan 2022 17:16:40 -0800 (PST) Received: by mail-pg1-x535.google.com with SMTP id s16so13765180pgs.13 for ; Mon, 31 Jan 2022 17:16:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=XvxcvzXH4VJ6E7zlHksxhLJ0Jar5RcY37sbz8vcUnwA=; b=n4Xh8YTEBFhu25veL76yREgUBbEjEjW92HU+rostZl5q2oTixGNege0DDfUmWh5Bul GSzaKNQNJMVDUaBazlPuwYdJZOsQ0OMS+GQuZ4FnrivwTO4qZ7J/MAWDUNoSQ4712tQn 5aIboyezBxyMpGb/KTKLzCiHWfGzCd7/RHNow= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=XvxcvzXH4VJ6E7zlHksxhLJ0Jar5RcY37sbz8vcUnwA=; b=nISevodoy3melxfgXtdEowhPuomERfYDrLLtHJ9gt92dPGOuw0w1zz+mfMji0LWHTp iWVeybeDPpZJEk3lROoaHOutDHQdcCD0Go4ipkJu0J33lGl2rk6umDu56wv0O4MalxKj KnDvZeB8F6xbdzcKOQh5LWolRAn73+naBIAY+RYELzSdGlmD3B88XkuDOeonSxSY+5mp mAVKRJvdeZeUf7qu/TUPR4LSSseCtQYsgsInOt5Rwvq/2LWfPAwBOCL2uqGMF/jtP/Lz 1xqDw6pP40R5p8K7305XWtu+oqp/sU8s4wOdeDD9cyOmQSzkEL1twY3Aa68tO8kS03gk t/KA== X-Gm-Message-State: AOAM5327ekuW9WmU7+X+ErdHsuHFj+dIqQJcdyh8ImpWlXNC0N48HAA8 MX4WnEmuGcmHI5ggavyf9CP8Gw== X-Google-Smtp-Source: ABdhPJygvz6vAby26Gb6IKXH4kaHD1Vneb7nQ+T6LqCv4x/uIdljdV6rZICzA999yVljOt7DA57yVQ== X-Received: by 2002:aa7:9682:: with SMTP id f2mr23009248pfk.56.1643678200095; Mon, 31 Jan 2022 17:16:40 -0800 (PST) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id o2sm29967814pga.57.2022.01.31.17.16.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 31 Jan 2022 17:16:39 -0800 (PST) From: Kees Cook To: Andrew Morton Cc: Kees Cook , Eric Biederman , Shuah Khan , Yang Yingliang , linux-kselftest@vger.kernel.org, Ariadne Conill , Michael Kerrisk , Matthew Wilcox , Christian Brauner , Rich Felker , Alexander Viro , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH] selftests/exec: Test for empty string on NULL argv Date: Mon, 31 Jan 2022 17:16:37 -0800 Message-Id: <20220201011637.2457646-1-keescook@chromium.org> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3353; h=from:subject; bh=KVYgP4gBGoag0XXkWLoVuF2irAM9dKCsptscwOX961o=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBh+In1d7YWRksOQF3vTA7Ad/dWv3vnj+wq4c1QUv75 5/y9xyWJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCYfiJ9QAKCRCJcvTf3G3AJmJnD/ wNNO8OqXL3vCcU15W01vFWGk7q8FIyycXT5RgTNAe//OMfilFwNRZrNrPk9oFOiNSgYOAKJ6ozi9kY GoeTNflQ3j6z03RmGX2kD3YZ7smAV/g5F6oL0+O7WKUMc1Qvh+Li6/8Dm+jZGi8EiL+qO9yWv6FU59 jEz0tPWDRtn+NLW0Yphtb9uWaY//uvnsBgw6MRmqRUVVZzDUyC4aB1KdjNF58CyCnVkpy/O9L/xhOl tlaNH7otK628H8Ed1jkhrJWiauj/vWIuxKUgdKFlPSIsZA/J/LoJ2rDMrMKQT6oDIlhrakwd0nfUt0 qSfH3XLWxI5Tv4SS2+6J1pLTSXUUrvYxLxcPpok48Xzn4gjVuEcvXR1G4PCh47oYVQwW3PqQ9I6VEr bL1Ld0cwSfKH0P4a5zpGpUp5I4OXmalSl0Lt/9PkoYi+wbHXC5a8NtnCnd5lawjxRDGv+WQF4P6F2C Yq5qFB6AykeZjD308o/V0ZfuwmaBknBpI/STtH0bHV0Q5rwJW8+DCMWTokojs2Nz/10dyCKAyOBO7V kej3JLmZTsoIg9ae80Qx5+SJjka3kmOGrLzoGPUlOnOK26JfJ1/wQExTmbiY+lAsNkrTGUDgDrg9q1 pHxqok5I3I5NWJTTpULhOke2pIC9DaH9KEUnohglrdlhgNRnQC6EnihEVS8A== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Test for the NULL argv argument producing a single empty string on exec. Cc: Eric Biederman Cc: Shuah Khan Cc: Yang Yingliang Cc: Andrew Morton Cc: linux-kselftest@vger.kernel.org Signed-off-by: Kees Cook --- This is testing for this patch: https://lore.kernel.org/linux-hardening/20220201000947.2453721-1-keescook@chromium.org/ --- tools/testing/selftests/exec/Makefile | 1 + tools/testing/selftests/exec/null-argv.c | 78 ++++++++++++++++++++++++ 2 files changed, 79 insertions(+) create mode 100644 tools/testing/selftests/exec/null-argv.c diff --git a/tools/testing/selftests/exec/Makefile b/tools/testing/selftests/exec/Makefile index dd61118df66e..4832cd8f4f9c 100644 --- a/tools/testing/selftests/exec/Makefile +++ b/tools/testing/selftests/exec/Makefile @@ -10,6 +10,7 @@ TEST_GEN_FILES := execveat.symlink execveat.denatured script subdir pipe TEST_FILES := Makefile TEST_GEN_PROGS += recursion-depth +TEST_GEN_PROGS += null-argv EXTRA_CLEAN := $(OUTPUT)/subdir.moved $(OUTPUT)/execveat.moved $(OUTPUT)/xxxxx* \ $(OUTPUT)/S_I*.test diff --git a/tools/testing/selftests/exec/null-argv.c b/tools/testing/selftests/exec/null-argv.c new file mode 100644 index 000000000000..c19726e710d1 --- /dev/null +++ b/tools/testing/selftests/exec/null-argv.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* Test that empty argvs are swapped out for a single empty string. */ +#include +#include +#include +#include + +#include "../kselftest.h" + +#define FORK(exec) \ +do { \ + pid = fork(); \ + if (pid == 0) { \ + /* Child */ \ + exec; /* Some kind of exec */ \ + perror("# " #exec); \ + return 1; \ + } \ + check_result(pid, #exec); \ +} while (0) + +void check_result(pid_t pid, const char *msg) +{ + int wstatus; + + if (pid == (pid_t)-1) { + perror("# fork"); + ksft_test_result_fail("fork failed: %s\n", msg); + return; + } + if (waitpid(pid, &wstatus, 0) < 0) { + perror("# waitpid"); + ksft_test_result_fail("waitpid failed: %s\n", msg); + return; + } + if (!WIFEXITED(wstatus)) { + ksft_test_result_fail("child did not exit: %s\n", msg); + return; + } + if (WEXITSTATUS(wstatus) != 0) { + ksft_test_result_fail("non-zero exit: %s\n", msg); + return; + } + ksft_test_result_pass("%s\n", msg); +} + +int main(int argc, char *argv[], char *envp[]) +{ + pid_t pid; + static char * const args[] = { NULL }; + static char * const str[] = { "", NULL }; + + /* argc counting checks */ + if (argc < 1) { + fprintf(stderr, "# FAIL: saw argc == 0 (old kernel?)\n"); + return 1; + } + if (argc != 1) { + fprintf(stderr, "# FAIL: unknown argc (%d)\n", argc); + return 1; + } + if (argv[0][0] == '\0') { + /* Good, we found a NULL terminated string at argv[0]! */ + return 0; + } + + /* Test runner. */ + ksft_print_header(); + ksft_set_plan(5); + + FORK(execve(argv[0], str, NULL)); + FORK(execve(argv[0], NULL, NULL)); + FORK(execve(argv[0], NULL, envp)); + FORK(execve(argv[0], args, NULL)); + FORK(execve(argv[0], args, envp)); + + ksft_exit(ksft_cnt.ksft_pass == ksft_plan); +}