From patchwork Thu May 23 12:42:16 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Potapenko X-Patchwork-Id: 10958183 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 1460B13AD for ; Thu, 23 May 2019 15:54:12 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 01BA51FF29 for ; Thu, 23 May 2019 15:54:12 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id EA48C28161; Thu, 23 May 2019 15:54:11 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-12.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED, USER_IN_DEF_DKIM_WL autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 8DDA127FA9 for ; Thu, 23 May 2019 15:54:10 +0000 (UTC) Received: (qmail 18203 invoked by uid 550); 23 May 2019 15:54:05 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Delivered-To: moderator for kernel-hardening@lists.openwall.com Received: (qmail 28094 invoked from network); 23 May 2019 12:42:50 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=GrPd0Ehzkwgs8flG0McuJvkTnr/DIjfrIhDeOSvXnoY=; b=c4PTxt6GbbkKh29sih5enoKVGyMiYVYDStyGmFdx5QefGnvHTake1qlrYrHoHEQrCE ++1kksetXbRrLBsUzGoBPVIMAAMNahTmjf785FIERAu9VEACDN6Dz1mlWOxOGpbeA7pb j/fU9z5gy2GIxuhbsTrOsbsC5W7GBJTGTn7dwa9/LCuRdsWwyAmoyq3PDyg5GU2ug5s+ HLYCxfheuLXUX4xre/bvMAurMTrcffJpEMMKp+j6Wtq8qnswrfxvwcbQ75DKYA0YMApY vroFWYFkyIu9Htfdesto2WrVrIfrGq7SCiUXYBDLUYAih13Eo2rIPWIc+nwn32ib129k jpNw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=GrPd0Ehzkwgs8flG0McuJvkTnr/DIjfrIhDeOSvXnoY=; b=ilx9QodUH01JyTOF0Q3xKVtaljAmkaNxcUXrVQkgyxSgLq4aMWV8hHhJbYVPX39d3l nixNvBW+jituulEEff9HuH4nL9j0Bi4DncmdvPEYPPXtO4ZQyf7UjAWYq7fQxRDel2dU OMbs+XdhMFW+ov+EOEM7yxDtzmW/m1q3YJp40YYdZmWNa4lrr6HGj6pLWHHC1brGai1v ShE5ozqBEZ23zHMzlWO5tNlGqtJ/SIg9Bi6tw489XGTkpOaCwFlB9U4bTB7aaDKWNwsI 98isgZU/3mzJ09pmuyeJYkGL7d7SzMdT5TdgirfMc0nQDLUX2FXl9NF6Tvr0UHe/xKms LE8g== X-Gm-Message-State: APjAAAWM7TmU758QNj6G5+gUaf8gAKZNp25ZC0VsjzNNk/u09ff/q26S R9LVRTkUL7rpboahk72+e/iKClCE4zk= X-Google-Smtp-Source: APXvYqx6+4Lx9KEyyCmocn+ERDYmrBvW59FCcdrGthGBmVTyeg7hNq7ggY14xUbi5JovTOJdj/wBvcGas8A= X-Received: by 2002:a5b:888:: with SMTP id e8mr12252456ybq.505.1558615359109; Thu, 23 May 2019 05:42:39 -0700 (PDT) Date: Thu, 23 May 2019 14:42:16 +0200 In-Reply-To: <20190523124216.40208-1-glider@google.com> Message-Id: <20190523124216.40208-4-glider@google.com> Mime-Version: 1.0 References: <20190523124216.40208-1-glider@google.com> X-Mailer: git-send-email 2.21.0.1020.gf2820cf01a-goog Subject: [PATCH 3/3] lib: introduce test_meminit module From: Alexander Potapenko To: akpm@linux-foundation.org, cl@linux.com, keescook@chromium.org Cc: kernel-hardening@lists.openwall.com, linux-mm@kvack.org, linux-security-module@vger.kernel.org, Nick Desaulniers , Kostya Serebryany , Dmitry Vyukov , Sandeep Patil , Laura Abbott , Jann Horn X-Virus-Scanned: ClamAV using ClamSMTP Add tests for heap and pagealloc initialization. These can be used to check init_on_alloc and init_on_free implementations as well as other approaches to initialization. Expected test output in the case the kernel provides heap initialization (e.g. when running with either init_on_alloc=1 or init_on_free=1): test_meminit: all 10 tests in test_pages passed test_meminit: all 40 tests in test_kvmalloc passed test_meminit: all 20 tests in test_kmemcache passed test_meminit: all 70 tests passed! Signed-off-by: Alexander Potapenko To: Kees Cook To: Andrew Morton To: Christoph Lameter Cc: Nick Desaulniers Cc: Kostya Serebryany Cc: Dmitry Vyukov Cc: Sandeep Patil Cc: Laura Abbott Cc: Jann Horn Cc: linux-mm@kvack.org Cc: linux-security-module@vger.kernel.org Cc: kernel-hardening@lists.openwall.com --- v3: - added example test output to the description - fixed a missing include spotted by kbuild test robot - added a missing MODULE_LICENSE - call do_kmem_cache_size() with size >= sizeof(void*) to unbreak debug builds --- lib/Kconfig.debug | 8 ++ lib/Makefile | 1 + lib/test_meminit.c | 208 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 217 insertions(+) create mode 100644 lib/test_meminit.c diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index fdfa173651eb..036e8ef03831 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2043,6 +2043,14 @@ config TEST_STACKINIT If unsure, say N. +config TEST_MEMINIT + tristate "Test level of heap/page initialization" + help + Test if the kernel is zero-initializing heap and page allocations. + This can be useful to test init_on_alloc and init_on_free features. + + If unsure, say N. + endif # RUNTIME_TESTING_MENU config MEMTEST diff --git a/lib/Makefile b/lib/Makefile index fb7697031a79..05980c802500 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -91,6 +91,7 @@ obj-$(CONFIG_TEST_DEBUG_VIRTUAL) += test_debug_virtual.o obj-$(CONFIG_TEST_MEMCAT_P) += test_memcat_p.o obj-$(CONFIG_TEST_OBJAGG) += test_objagg.o obj-$(CONFIG_TEST_STACKINIT) += test_stackinit.o +obj-$(CONFIG_TEST_MEMINIT) += test_meminit.o obj-$(CONFIG_TEST_LIVEPATCH) += livepatch/ diff --git a/lib/test_meminit.c b/lib/test_meminit.c new file mode 100644 index 000000000000..d46e2b8c8e8e --- /dev/null +++ b/lib/test_meminit.c @@ -0,0 +1,208 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test cases for SL[AOU]B/page initialization at alloc/free time. + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include + +#define GARBAGE_INT (0x09A7BA9E) +#define GARBAGE_BYTE (0x9E) + +#define REPORT_FAILURES_IN_FN() \ + do { \ + if (failures) \ + pr_info("%s failed %d out of %d times\n", \ + __func__, failures, num_tests); \ + else \ + pr_info("all %d tests in %s passed\n", \ + num_tests, __func__); \ + } while (0) + +/* Calculate the number of uninitialized bytes in the buffer. */ +static int count_nonzero_bytes(void *ptr, size_t size) +{ + int i, ret = 0; + unsigned char *p = (unsigned char *)ptr; + + for (i = 0; i < size; i++) + if (p[i]) + ret++; + return ret; +} + +static void fill_with_garbage(void *ptr, size_t size) +{ + unsigned int *p = (unsigned int *)ptr; + int i = 0; + + while (size >= sizeof(*p)) { + p[i] = GARBAGE_INT; + i++; + size -= sizeof(*p); + } + if (size) + memset(&p[i], GARBAGE_BYTE, size); +} + +static int __init do_alloc_pages_order(int order, int *total_failures) +{ + struct page *page; + void *buf; + size_t size = PAGE_SIZE << order; + + page = alloc_pages(GFP_KERNEL, order); + buf = page_address(page); + fill_with_garbage(buf, size); + __free_pages(page, order); + + page = alloc_pages(GFP_KERNEL, order); + buf = page_address(page); + if (count_nonzero_bytes(buf, size)) + (*total_failures)++; + fill_with_garbage(buf, size); + __free_pages(page, order); + return 1; +} + +static int __init test_pages(int *total_failures) +{ + int failures = 0, num_tests = 0; + int i; + + for (i = 0; i < 10; i++) + num_tests += do_alloc_pages_order(i, &failures); + + REPORT_FAILURES_IN_FN(); + *total_failures += failures; + return num_tests; +} + +static int __init do_kmalloc_size(size_t size, int *total_failures) +{ + void *buf; + + buf = kmalloc(size, GFP_KERNEL); + fill_with_garbage(buf, size); + kfree(buf); + + buf = kmalloc(size, GFP_KERNEL); + if (count_nonzero_bytes(buf, size)) + (*total_failures)++; + fill_with_garbage(buf, size); + kfree(buf); + return 1; +} + +static int __init do_vmalloc_size(size_t size, int *total_failures) +{ + void *buf; + + buf = vmalloc(size); + fill_with_garbage(buf, size); + vfree(buf); + + buf = vmalloc(size); + if (count_nonzero_bytes(buf, size)) + (*total_failures)++; + fill_with_garbage(buf, size); + vfree(buf); + return 1; +} + +static int __init test_kvmalloc(int *total_failures) +{ + int failures = 0, num_tests = 0; + int i, size; + + for (i = 0; i < 20; i++) { + size = 1 << i; + num_tests += do_kmalloc_size(size, &failures); + num_tests += do_vmalloc_size(size, &failures); + } + + REPORT_FAILURES_IN_FN(); + *total_failures += failures; + return num_tests; +} + +#define CTOR_BYTES 4 +/* Initialize the first 4 bytes of the object. */ +void some_ctor(void *obj) +{ + memset(obj, 'A', CTOR_BYTES); +} + +static int __init do_kmem_cache_size(size_t size, bool want_ctor, + int *total_failures) +{ + struct kmem_cache *c; + void *buf; + int iter, bytes = 0; + int fail = 0; + + c = kmem_cache_create("test_cache", size, 1, 0, + want_ctor ? some_ctor : NULL); + for (iter = 0; iter < 10; iter++) { + buf = kmem_cache_alloc(c, GFP_KERNEL); + if (!want_ctor || iter == 0) + bytes = count_nonzero_bytes(buf, size); + if (want_ctor) { + /* + * Newly initialized memory must be initialized using + * the constructor. + */ + if (iter == 0 && bytes < CTOR_BYTES) + fail = 1; + } else { + if (bytes) + fail = 1; + } + fill_with_garbage(buf, size); + kmem_cache_free(c, buf); + } + kmem_cache_destroy(c); + + *total_failures += fail; + return 1; +} + +static int __init test_kmemcache(int *total_failures) +{ + int failures = 0, num_tests = 0; + int i, size; + + for (i = 0; i < 10; i++) { + size = 8 << i; + num_tests += do_kmem_cache_size(size, false, &failures); + num_tests += do_kmem_cache_size(size, true, &failures); + } + REPORT_FAILURES_IN_FN(); + *total_failures += failures; + return num_tests; +} + +static int __init test_meminit_init(void) +{ + int failures = 0, num_tests = 0; + + num_tests += test_pages(&failures); + num_tests += test_kvmalloc(&failures); + num_tests += test_kmemcache(&failures); + + if (failures == 0) + pr_info("all %d tests passed!\n", num_tests); + else + pr_info("failures: %d out of %d\n", failures, num_tests); + + return failures ? -EINVAL : 0; +} +module_init(test_meminit_init); + +MODULE_LICENSE("GPL");