From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qa0-f41.google.com (mail-qa0-f41.google.com [209.85.216.41]) by kanga.kvack.org (Postfix) with ESMTP id 44EA06B0039 for ; Fri, 26 Sep 2014 13:12:10 -0400 (EDT) Received: by mail-qa0-f41.google.com with SMTP id cm18so6446638qab.14 for ; Fri, 26 Sep 2014 10:12:10 -0700 (PDT) Received: from mail-qc0-x22d.google.com (mail-qc0-x22d.google.com [2607:f8b0:400d:c01::22d]) by mx.google.com with ESMTPS id 32si6595800qgc.1.2014.09.26.10.12.09 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Fri, 26 Sep 2014 10:12:09 -0700 (PDT) Received: by mail-qc0-f173.google.com with SMTP id r5so4845420qcx.18 for ; Fri, 26 Sep 2014 10:12:09 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1411562649-28231-13-git-send-email-a.ryabinin@samsung.com> References: <1404905415-9046-1-git-send-email-a.ryabinin@samsung.com> <1411562649-28231-1-git-send-email-a.ryabinin@samsung.com> <1411562649-28231-13-git-send-email-a.ryabinin@samsung.com> From: Dmitry Vyukov Date: Fri, 26 Sep 2014 10:11:49 -0700 Message-ID: Subject: Re: [PATCH v3 12/13] lib: add kasan test module Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Andrey Ryabinin Cc: LKML , Konstantin Serebryany , Dmitry Chernenkov , Andrey Konovalov , Yuri Gribov , Konstantin Khlebnikov , Sasha Levin , Christoph Lameter , Joonsoo Kim , Andrew Morton , Dave Hansen , Andi Kleen , Vegard Nossum , "H. Peter Anvin" , Dave Jones , x86@kernel.org, linux-mm@kvack.org Looks good to me. On Wed, Sep 24, 2014 at 5:44 AM, Andrey Ryabinin wrote: > This is a test module doing varios nasty things like > out of bounds accesses, use after free. It is usefull for testing > kernel debugging features like kernel address sanitizer. > > It mostly concentrates on testing of slab allocator, but we > might want to add more different stuff here in future (like > stack/global variables out of bounds accesses and so on). > > Signed-off-by: Andrey Ryabinin > --- > lib/Kconfig.kasan | 8 ++ > lib/Makefile | 1 + > lib/test_kasan.c | 254 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 263 insertions(+) > create mode 100644 lib/test_kasan.c > > diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan > index d16b899..faddb0e 100644 > --- a/lib/Kconfig.kasan > +++ b/lib/Kconfig.kasan > @@ -19,4 +19,12 @@ config KASAN_SHADOW_OFFSET > hex > default 0xdfffe90000000000 if X86_64 > > +config TEST_KASAN > + tristate "Module for testing kasan for bug detection" > + depends on m > + help > + This is a test module doing varios nasty things like > + out of bounds accesses, use after free. It is usefull for testing > + kernel debugging features like kernel address sanitizer. > + > endif > diff --git a/lib/Makefile b/lib/Makefile > index 84a56f7..d620d27 100644 > --- a/lib/Makefile > +++ b/lib/Makefile > @@ -35,6 +35,7 @@ obj-$(CONFIG_TEST_MODULE) += test_module.o > obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o > obj-$(CONFIG_TEST_BPF) += test_bpf.o > obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o > +obj-$(CONFIG_TEST_KASAN) += test_kasan.o > > ifeq ($(CONFIG_DEBUG_KOBJECT),y) > CFLAGS_kobject.o += -DDEBUG > diff --git a/lib/test_kasan.c b/lib/test_kasan.c > new file mode 100644 > index 0000000..66a04eb > --- /dev/null > +++ b/lib/test_kasan.c > @@ -0,0 +1,254 @@ > +/* > + * > + * Copyright (c) 2014 Samsung Electronics Co., Ltd. > + * Author: Andrey Ryabinin > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + */ > + > +#define pr_fmt(fmt) "kasan test: %s " fmt, __func__ > + > +#include > +#include > +#include > +#include > +#include > + > +static noinline void __init kmalloc_oob_right(void) > +{ > + char *ptr; > + size_t size = 123; > + > + pr_info("out-of-bounds to right\n"); > + ptr = kmalloc(size , GFP_KERNEL); > + if (!ptr) { > + pr_err("Allocation failed\n"); > + return; > + } > + > + ptr[size] = 'x'; > + kfree(ptr); > +} > + > +static noinline void __init kmalloc_oob_left(void) > +{ > + char *ptr; > + size_t size = 15; > + > + pr_info("out-of-bounds to left\n"); > + ptr = kmalloc(size, GFP_KERNEL); > + if (!ptr) { > + pr_err("Allocation failed\n"); > + return; > + } > + > + *ptr = *(ptr - 1); > + kfree(ptr); > +} > + > +static noinline void __init kmalloc_node_oob_right(void) > +{ > + char *ptr; > + size_t size = 4096; > + > + pr_info("kmalloc_node(): out-of-bounds to right\n"); > + ptr = kmalloc_node(size , GFP_KERNEL, 0); > + if (!ptr) { > + pr_err("Allocation failed\n"); > + return; > + } > + > + ptr[size] = 0; > + kfree(ptr); > +} > + > +static noinline void __init kmalloc_large_oob_rigth(void) > +{ > + char *ptr; > + size_t size = KMALLOC_MAX_CACHE_SIZE + 10; > + > + pr_info("kmalloc large allocation: out-of-bounds to right\n"); > + ptr = kmalloc(size , GFP_KERNEL); > + if (!ptr) { > + pr_err("Allocation failed\n"); > + return; > + } > + > + ptr[size] = 0; > + kfree(ptr); > +} > + > +static noinline void __init kmalloc_oob_krealloc_more(void) > +{ > + char *ptr1, *ptr2; > + size_t size1 = 17; > + size_t size2 = 19; > + > + pr_info("out-of-bounds after krealloc more\n"); > + ptr1 = kmalloc(size1, GFP_KERNEL); > + ptr2 = krealloc(ptr1, size2, GFP_KERNEL); > + if (!ptr1 || !ptr2) { > + pr_err("Allocation failed\n"); > + kfree(ptr1); > + return; > + } > + > + ptr2[size2] = 'x'; > + kfree(ptr2); > +} > + > +static noinline void __init kmalloc_oob_krealloc_less(void) > +{ > + char *ptr1, *ptr2; > + size_t size1 = 17; > + size_t size2 = 15; > + > + pr_info("out-of-bounds after krealloc less\n"); > + ptr1 = kmalloc(size1, GFP_KERNEL); > + ptr2 = krealloc(ptr1, size2, GFP_KERNEL); > + if (!ptr1 || !ptr2) { > + pr_err("Allocation failed\n"); > + kfree(ptr1); > + return; > + } > + ptr2[size1] = 'x'; > + kfree(ptr2); > +} > + > +static noinline void __init kmalloc_oob_16(void) > +{ > + struct { > + u64 words[2]; > + } *ptr1, *ptr2; > + > + pr_info("kmalloc out-of-bounds for 16-bytes access\n"); > + ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL); > + ptr2 = kmalloc(sizeof(*ptr2), GFP_KERNEL); > + if (!ptr1 || !ptr2) { > + pr_err("Allocation failed\n"); > + kfree(ptr1); > + kfree(ptr2); > + return; > + } > + *ptr1 = *ptr2; > + kfree(ptr1); > + kfree(ptr2); > +} > + > +static noinline void __init kmalloc_oob_in_memset(void) > +{ > + char *ptr; > + size_t size = 666; > + > + pr_info("out-of-bounds in memset\n"); > + ptr = kmalloc(size, GFP_KERNEL); > + if (!ptr) { > + pr_err("Allocation failed\n"); > + return; > + } > + > + memset(ptr, 0, size+5); > + kfree(ptr); > +} > + > +static noinline void __init kmalloc_uaf(void) > +{ > + char *ptr; > + size_t size = 10; > + > + pr_info("use-after-free\n"); > + ptr = kmalloc(size, GFP_KERNEL); > + if (!ptr) { > + pr_err("Allocation failed\n"); > + return; > + } > + > + kfree(ptr); > + *(ptr + 8) = 'x'; > +} > + > +static noinline void __init kmalloc_uaf_memset(void) > +{ > + char *ptr; > + size_t size = 33; > + > + pr_info("use-after-free in memset\n"); > + ptr = kmalloc(size, GFP_KERNEL); > + if (!ptr) { > + pr_err("Allocation failed\n"); > + return; > + } > + > + kfree(ptr); > + memset(ptr, 0, size); > +} > + > +static noinline void __init kmalloc_uaf2(void) > +{ > + char *ptr1, *ptr2; > + size_t size = 43; > + > + pr_info("use-after-free after another kmalloc\n"); > + ptr1 = kmalloc(size, GFP_KERNEL); > + if (!ptr1) { > + pr_err("Allocation failed\n"); > + return; > + } > + > + kfree(ptr1); > + ptr2 = kmalloc(size, GFP_KERNEL); > + if (!ptr2) { > + pr_err("Allocation failed\n"); > + return; > + } > + > + ptr1[40] = 'x'; > + kfree(ptr2); > +} > + > +static noinline void __init kmem_cache_oob(void) > +{ > + char *p; > + size_t size = 200; > + struct kmem_cache *cache = kmem_cache_create("test_cache", > + size, 0, > + 0, NULL); > + if (!cache) { > + pr_err("Cache allocation failed\n"); > + return; > + } > + pr_info("out-of-bounds in kmem_cache_alloc\n"); > + p = kmem_cache_alloc(cache, GFP_KERNEL); > + if (!p) { > + pr_err("Allocation failed\n"); > + kmem_cache_destroy(cache); > + return; > + } > + > + *p = p[size]; > + kmem_cache_free(cache, p); > + kmem_cache_destroy(cache); > +} > + > +int __init kmalloc_tests_init(void) > +{ > + kmalloc_oob_right(); > + kmalloc_oob_left(); > + kmalloc_node_oob_right(); > + kmalloc_large_oob_rigth(); > + kmalloc_oob_krealloc_more(); > + kmalloc_oob_krealloc_less(); > + kmalloc_oob_16(); > + kmalloc_oob_in_memset(); > + kmalloc_uaf(); > + kmalloc_uaf_memset(); > + kmalloc_uaf2(); > + kmem_cache_oob(); > + return -EAGAIN; > +} > + > +module_init(kmalloc_tests_init); > +MODULE_LICENSE("GPL"); > -- > 2.1.1 > -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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