From patchwork Wed Nov 20 01:06:34 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11252949 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B53C61390 for ; Wed, 20 Nov 2019 01:07:19 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 144E920708 for ; Wed, 20 Nov 2019 01:07:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="GjW65mTR" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 144E920708 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-17406-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 26020 invoked by uid 550); 20 Nov 2019 01:06:58 -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 Received: (qmail 25793 invoked from network); 20 Nov 2019 01:06:56 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=cO8TBOltsH4skyCZjRFi1jjLHEcJb6wGQF3Nty2AFlw=; b=GjW65mTRpHcwke1tPpXJc+tEroqq+/c02L1weluBXv2HYDmUvuJroQHtjQB47mZ+Dq XrKKO4SSKAvPWN92dzPW6/GSh6v84X+1ecqKm5cP0W3j1AZS9WEFrXlA9digFiGFRewB KhiECAt/oiWz0Q2+iz92oxoX7RzTYeQrdzJTo= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=cO8TBOltsH4skyCZjRFi1jjLHEcJb6wGQF3Nty2AFlw=; b=Klu8EFKd70LrRc0VHyGe6tqhpFFuTFoEzchVq3FApjpNl7agzBvR1+NGvqczKv34kV BtbpSTmW9ToFbyNIzP28X1JE6bglIsI9Wg10tmf2MPJrZN/MJM2d+mptovatZ8f8G97c DDFCgxOuRXrTmLnEpy520465fpo8OWv/26DXzcoPn8jNnH8Qk8sLpp2enYJTVDjLenNS dnRpcWYAHnp6iZb3AJ+sYKHegenoTouWW+Fnn/FgeTfWrh8YOedH1Y1Uw9Uyi008aTpX 8lupWVf/2f88xPCVtAhoN9YpXjfbCcLZHg9DviTaLk8yYB5PrNMn3E+lX29b7eEBXwHp dHYQ== X-Gm-Message-State: APjAAAUJzGl3isCVXiZfOc1YBcXDU8AbbfHC9IOHhX0DQ0RAY7nHXf9i LPxdjUoriOYXUe8Qw9T7ZKFMGA== X-Google-Smtp-Source: APXvYqyASvZYvBQ/e7CI9HnVv6bkAWB/563LT5YKo0qEsvHWgg7DJbmwdBC/nFhsf8xhjPvdZtXPKw== X-Received: by 2002:aa7:9f89:: with SMTP id z9mr651850pfr.123.1574212004404; Tue, 19 Nov 2019 17:06:44 -0800 (PST) From: Kees Cook To: Andrey Ryabinin Cc: Kees Cook , Elena Petrova , Alexander Potapenko , Dmitry Vyukov , Linus Torvalds , Dan Carpenter , "Gustavo A. R. Silva" , Arnd Bergmann , Ard Biesheuvel , Andrew Morton , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com Subject: [PATCH 1/3] ubsan: Add trap instrumentation option Date: Tue, 19 Nov 2019 17:06:34 -0800 Message-Id: <20191120010636.27368-2-keescook@chromium.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191120010636.27368-1-keescook@chromium.org> References: <20191120010636.27368-1-keescook@chromium.org> The Undefined Behavior Sanitizer can operate in two modes: warning reporting mode via lib/ubsan.c handler calls, or trap mode, which uses __builtin_trap() as the handler. Using lib/ubsan.c means the kernel image is about 5% larger (due to all the debugging text and reporting structures to capture details about the warning conditions). Using the trap mode, the image size changes are much smaller, though at the loss of the "warning only" mode. In order to give greater flexibility to system builders that want minimal changes to image size and are prepared to deal with kernel threads being killed, this introduces CONFIG_UBSAN_TRAP. The resulting image sizes comparison: text data bss dec hex filename 19533663 6183037 18554956 44271656 2a38828 vmlinux.stock 19991849 7618513 18874448 46484810 2c54d4a vmlinux.ubsan 19712181 6284181 18366540 44362902 2a4ec96 vmlinux.ubsan-trap CONFIG_UBSAN=y: image +4.8% (text +2.3%, data +18.9%) CONFIG_UBSAN_TRAP=y: image +0.2% (text +0.9%, data +1.6%) Suggested-by: Elena Petrova Signed-off-by: Kees Cook --- lib/Kconfig.ubsan | 15 +++++++++++++-- lib/Makefile | 2 ++ scripts/Makefile.ubsan | 9 +++++++-- 3 files changed, 22 insertions(+), 4 deletions(-) diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index 0e04fcb3ab3d..d69e8b21ebae 100644 --- a/lib/Kconfig.ubsan +++ b/lib/Kconfig.ubsan @@ -5,12 +5,23 @@ config ARCH_HAS_UBSAN_SANITIZE_ALL config UBSAN bool "Undefined behaviour sanity checker" help - This option enables undefined behaviour sanity checker + This option enables undefined behaviour sanity checker. Compile-time instrumentation is used to detect various undefined - behaviours in runtime. Various types of checks may be enabled + behaviours at runtime. Various types of checks may be enabled via boot parameter ubsan_handle (see: Documentation/dev-tools/ubsan.rst). +config UBSAN_TRAP + bool "On Sanitizer warnings, stop the offending kernel thread" + depends on UBSAN + depends on $(cc-option, -fsanitize-undefined-trap-on-error) + help + Building kernels with Sanitizer features enabled tends to grow + the kernel size by over 5%, due to adding all the debugging + text on failure paths. To avoid this, Sanitizer instrumentation + can just issue a trap. This reduces the kernel size overhead but + turns all warnings into full thread-killing exceptions. + config UBSAN_SANITIZE_ALL bool "Enable instrumentation for the entire kernel" depends on UBSAN diff --git a/lib/Makefile b/lib/Makefile index c5892807e06f..bc498bf0f52d 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -272,7 +272,9 @@ quiet_cmd_build_OID_registry = GEN $@ clean-files += oid_registry_data.c obj-$(CONFIG_UCS2_STRING) += ucs2_string.o +ifneq ($(CONFIG_UBSAN_TRAP),y) obj-$(CONFIG_UBSAN) += ubsan.o +endif UBSAN_SANITIZE_ubsan.o := n KASAN_SANITIZE_ubsan.o := n diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan index 019771b845c5..668a91510bfe 100644 --- a/scripts/Makefile.ubsan +++ b/scripts/Makefile.ubsan @@ -1,5 +1,10 @@ # SPDX-License-Identifier: GPL-2.0 ifdef CONFIG_UBSAN + +ifdef CONFIG_UBSAN_ALIGNMENT + CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment) +endif + CFLAGS_UBSAN += $(call cc-option, -fsanitize=shift) CFLAGS_UBSAN += $(call cc-option, -fsanitize=integer-divide-by-zero) CFLAGS_UBSAN += $(call cc-option, -fsanitize=unreachable) @@ -9,8 +14,8 @@ ifdef CONFIG_UBSAN CFLAGS_UBSAN += $(call cc-option, -fsanitize=bool) CFLAGS_UBSAN += $(call cc-option, -fsanitize=enum) -ifdef CONFIG_UBSAN_ALIGNMENT - CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment) +ifdef CONFIG_UBSAN_TRAP + CFLAGS_UBSAN += $(call cc-option, -fsanitize-undefined-trap-on-error) endif # -fsanitize=* options makes GCC less smart than usual and From patchwork Wed Nov 20 01:06:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11252945 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0DF8E1593 for ; Wed, 20 Nov 2019 01:07:05 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 60EAB2245C for ; Wed, 20 Nov 2019 01:07:04 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="Dl72hrPu" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 60EAB2245C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-17404-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 25791 invoked by uid 550); 20 Nov 2019 01:06:56 -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 Received: (qmail 24562 invoked from network); 20 Nov 2019 01:06:54 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Qk+ofBX2bx2BOGB4TqoJ+/VT2N5xkCBYGbqC21Di0lw=; b=Dl72hrPuwamrfPqyV6plvaUBtf5zRowEghIpoZqmgJgFOczuF7EKzjTanI6iefsS9Z 9TvygmIVih8TjwrgaGRcecyP/tDTc7gHkW1za6Qsa+kQOjj0UpGf+owodcIUwPQ/ZSDu QgLC6/NCcIR5lG7LQGAW6FZc2y8odHX4FtywQ= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=Qk+ofBX2bx2BOGB4TqoJ+/VT2N5xkCBYGbqC21Di0lw=; b=N4XlaO1KwOUk5LzqSY2QnX0XFOFkZdjCs9OT+TXgLu2cPAHJHe45Y3Rt4/Z9f5pu0W 59tOqw07/BbRmKp0OPAjzKM/AjG7p27POMtlhfKSHz4EffwIN4mt2JbIpOS3N/2+enAD aIzZyviV5dGa2wxYjF25CIv1WpAVXrYIXJUT8jxEDgJUBxx7FT6o8Qd1G2lVNz6ktKJt KfVskm467nF4juXF3aacZ1ToAcwh3Plku+AbM5S7knoEDld9xwMFyRAJC0xQAum6Phpu MhSYTTpTJeHQmI+5LsLhrS5LbMMhqDkFCkV4iRpWfU46MwJ3uy6+98DvuC4e6lwxDC8T Uq/g== X-Gm-Message-State: APjAAAWLRGSv+PZBPVXtt109hif+PUO7CPQrm5GKCUEwNfwUyd5LiJmw 80MJyAyhJ/LQzlh5eKpjlhlQdA== X-Google-Smtp-Source: APXvYqwU4vILON4RTm6tdSJVl700JzP/ajHyi1fFkaWh7maGAK9WWWqyZPY7AO1vwzjH8oRIUlhNnw== X-Received: by 2002:a63:5d10:: with SMTP id r16mr80693pgb.41.1574212003024; Tue, 19 Nov 2019 17:06:43 -0800 (PST) From: Kees Cook To: Andrey Ryabinin Cc: Kees Cook , Elena Petrova , Alexander Potapenko , Dmitry Vyukov , Linus Torvalds , Dan Carpenter , "Gustavo A. R. Silva" , Arnd Bergmann , Ard Biesheuvel , Andrew Morton , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com Subject: [PATCH 2/3] ubsan: Split "bounds" checker from other options Date: Tue, 19 Nov 2019 17:06:35 -0800 Message-Id: <20191120010636.27368-3-keescook@chromium.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191120010636.27368-1-keescook@chromium.org> References: <20191120010636.27368-1-keescook@chromium.org> In order to do kernel builds with the bounds checker individually available, introduce CONFIG_UBSAN_BOUNDS, with the remaining options under CONFIG_UBSAN_MISC. For example, using this, we can start to expand the coverage syzkaller is providing. Right now, all of UBSan is disabled for syzbot builds because taken as a whole, it is too noisy. This will let us focus on one feature at a time. For the bounds checker specifically, this provides a mechanism to eliminate an entire class of array overflows with close to zero performance overhead (I cannot measure a difference). In my (mostly) defconfig, enabling bounds checking adds ~4200 checks to the kernel. Performance changes are in the noise, likely due to the branch predictors optimizing for the non-fail path. Some notes on the bounds checker: - it does not instrument {mem,str}*()-family functions, it only instruments direct indexed accesses (e.g. "foo[i]"). Dealing with the {mem,str}*()-family functions is a work-in-progress around CONFIG_FORTIFY_SOURCE[1]. - it ignores flexible array members, including the very old single byte (e.g. "int foo[1];") declarations. (Note that GCC's implementation appears to ignore _all_ trailing arrays, but Clang only ignores empty, 0, and 1 byte arrays[2].) [1] https://github.com/KSPP/linux/issues/6 [2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92589 Suggested-by: Elena Petrova Signed-off-by: Kees Cook Reviewed-by: Andrey Ryabinin --- lib/Kconfig.ubsan | 19 +++++++++++++++++++ scripts/Makefile.ubsan | 7 ++++++- 2 files changed, 25 insertions(+), 1 deletion(-) diff --git a/lib/Kconfig.ubsan b/lib/Kconfig.ubsan index d69e8b21ebae..f5ed2dceef30 100644 --- a/lib/Kconfig.ubsan +++ b/lib/Kconfig.ubsan @@ -22,6 +22,25 @@ config UBSAN_TRAP can just issue a trap. This reduces the kernel size overhead but turns all warnings into full thread-killing exceptions. +config UBSAN_BOUNDS + bool "Perform array bounds checking" + depends on UBSAN + default UBSAN + help + This option enables detection of direct out of bounds array + accesses, where the array size is known at compile time. Note + that this does not protect character array overflows due to + bad calls to the {str,mem}*cpy() family of functions. + +config UBSAN_MISC + bool "Enable all other Undefined Behavior sanity checks" + depends on UBSAN + default UBSAN + help + This option enables all sanity checks that don't have their + own Kconfig options. Disable this if you only want to have + individually selected checks. + config UBSAN_SANITIZE_ALL bool "Enable instrumentation for the entire kernel" depends on UBSAN diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan index 668a91510bfe..5b15bc425ec9 100644 --- a/scripts/Makefile.ubsan +++ b/scripts/Makefile.ubsan @@ -5,14 +5,19 @@ ifdef CONFIG_UBSAN_ALIGNMENT CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment) endif +ifdef CONFIG_UBSAN_BOUNDS + CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds) +endif + +ifdef CONFIG_UBSAN_MISC CFLAGS_UBSAN += $(call cc-option, -fsanitize=shift) CFLAGS_UBSAN += $(call cc-option, -fsanitize=integer-divide-by-zero) CFLAGS_UBSAN += $(call cc-option, -fsanitize=unreachable) CFLAGS_UBSAN += $(call cc-option, -fsanitize=signed-integer-overflow) - CFLAGS_UBSAN += $(call cc-option, -fsanitize=bounds) CFLAGS_UBSAN += $(call cc-option, -fsanitize=object-size) CFLAGS_UBSAN += $(call cc-option, -fsanitize=bool) CFLAGS_UBSAN += $(call cc-option, -fsanitize=enum) +endif ifdef CONFIG_UBSAN_TRAP CFLAGS_UBSAN += $(call cc-option, -fsanitize-undefined-trap-on-error) From patchwork Wed Nov 20 01:06:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11252947 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 256DE1593 for ; Wed, 20 Nov 2019 01:07:12 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 7B0102245C for ; Wed, 20 Nov 2019 01:07:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="a82EApFV" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B0102245C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-17405-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 25902 invoked by uid 550); 20 Nov 2019 01:06:57 -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 Received: (qmail 25778 invoked from network); 20 Nov 2019 01:06:56 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=0T61AzxnAvwa4rB+CZumfDDidufAJnp+U8GPCQMxTB4=; b=a82EApFVTEe9phvCSrJOP3TlCmeHwEbc7lBntv/Y4A3SIjXWLzIYaza53B34WSAvIO M/p/3ECy6DvVgT1DcT27ZKc9hqk61OMYWbeg8Ie4sWtPigLH57V9lJaYWI9PwzZgGuQN +goyCf8HKTHNdfpJZrJyL8SxxITM+b1kefwFs= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=0T61AzxnAvwa4rB+CZumfDDidufAJnp+U8GPCQMxTB4=; b=Nf/iZF9dOTWItmVOBMofCzGW9TQY6EG/BJrFuCWkCQ6qJUvN2PNdIo7C+5KdBPD/Qh thlASSlaCux0IN+izLW7OVtrTd9aSw9yqfRoHedug/UDPO65OM6Zwzta+1kXVsdjZwEV yhEmMfvvW3DwuqB0HxhIBB59LUKSIsmqmyy/I1uAWyjwtl0UyXXTUfsjtIfp6B1Bpgjd LpS2pL64H6t/MWGPQYNxbo4mR4iCZ6aR1d28lWhXbtYOj85CkRprk1Gy7eJu24t0EUxI 1px9l609K75l9LCX44OvByAVv8xngIoP/C/tZnXNrQaqutdTQypFQS21GeTBUteb3IHN 3oDw== X-Gm-Message-State: APjAAAVeNjeDqsE+QHRVA+A9S9Ls6Hmhyi64RFiXAiXNoghCTNzpQ1XT CmvOOoZgLzuym+08Bj8UELTHFA== X-Google-Smtp-Source: APXvYqwMjjdQ2rf3CZ9jjyiv4G3ZP7tQU+Lm0RTG8f4dInndtCYLfPklkPViLPE1GjBEoqneZ6KF6w== X-Received: by 2002:a17:902:561:: with SMTP id 88mr155318plf.127.1574212003854; Tue, 19 Nov 2019 17:06:43 -0800 (PST) From: Kees Cook To: Andrey Ryabinin Cc: Kees Cook , Elena Petrova , Alexander Potapenko , Dmitry Vyukov , Linus Torvalds , Dan Carpenter , "Gustavo A. R. Silva" , Arnd Bergmann , Ard Biesheuvel , Andrew Morton , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com Subject: [PATCH 3/3] lkdtm/bugs: Add arithmetic overflow and array bounds checks Date: Tue, 19 Nov 2019 17:06:36 -0800 Message-Id: <20191120010636.27368-4-keescook@chromium.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191120010636.27368-1-keescook@chromium.org> References: <20191120010636.27368-1-keescook@chromium.org> Adds LKDTM tests for arithmetic overflow (both signed and unsigned), as well as array bounds checking. Signed-off-by: Kees Cook --- drivers/misc/lkdtm/bugs.c | 75 ++++++++++++++++++++++++++++++++++++++ drivers/misc/lkdtm/core.c | 3 ++ drivers/misc/lkdtm/lkdtm.h | 3 ++ 3 files changed, 81 insertions(+) diff --git a/drivers/misc/lkdtm/bugs.c b/drivers/misc/lkdtm/bugs.c index 7284a22b1a09..8b4ef30f53c6 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -11,6 +11,7 @@ #include #include #include +#include struct lkdtm_list { struct list_head node; @@ -171,6 +172,80 @@ void lkdtm_HUNG_TASK(void) schedule(); } +volatile unsigned int huge = INT_MAX - 2; +volatile unsigned int ignored; + +void lkdtm_OVERFLOW_SIGNED(void) +{ + int value; + + value = huge; + pr_info("Normal signed addition ...\n"); + value += 1; + ignored = value; + + pr_info("Overflowing signed addition ...\n"); + value += 4; + ignored = value; +} + + +void lkdtm_OVERFLOW_UNSIGNED(void) +{ + unsigned int value; + + value = huge; + pr_info("Normal unsigned addition ...\n"); + value += 1; + ignored = value; + + pr_info("Overflowing unsigned addition ...\n"); + value += 4; + ignored = value; +} + +/* Intentially using old-style flex array definition of 1 byte. */ +struct array_bounds_flex_array { + int one; + int two; + char data[1]; +}; + +struct array_bounds { + int one; + int two; + char data[8]; + int three; +}; + +void lkdtm_ARRAY_BOUNDS(void) +{ + struct array_bounds_flex_array *not_checked; + struct array_bounds *checked; + int i; + + not_checked = kmalloc(sizeof(*not_checked) * 2, GFP_KERNEL); + checked = kmalloc(sizeof(*checked) * 2, GFP_KERNEL); + + pr_info("Array access within bounds ...\n"); + /* For both, touch all bytes in the actual member size. */ + for (i = 0; i < sizeof(checked->data); i++) + checked->data[i] = 'A'; + /* + * For the uninstrumented flex array member, also touch 1 byte + * beyond to verify it is correctly uninstrumented. + */ + for (i = 0; i < sizeof(not_checked->data) + 1; i++) + not_checked->data[i] = 'A'; + + pr_info("Array access beyond bounds ...\n"); + for (i = 0; i < sizeof(checked->data) + 1; i++) + checked->data[i] = 'B'; + + kfree(not_checked); + kfree(checked); +} + void lkdtm_CORRUPT_LIST_ADD(void) { /* diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c index cbc4c9045a99..25879f7b0768 100644 --- a/drivers/misc/lkdtm/core.c +++ b/drivers/misc/lkdtm/core.c @@ -129,6 +129,9 @@ static const struct crashtype crashtypes[] = { CRASHTYPE(HARDLOCKUP), CRASHTYPE(SPINLOCKUP), CRASHTYPE(HUNG_TASK), + CRASHTYPE(OVERFLOW_SIGNED), + CRASHTYPE(OVERFLOW_UNSIGNED), + CRASHTYPE(ARRAY_BOUNDS), CRASHTYPE(EXEC_DATA), CRASHTYPE(EXEC_STACK), CRASHTYPE(EXEC_KMALLOC), diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h index ab446e0bde97..2cd0c5031eea 100644 --- a/drivers/misc/lkdtm/lkdtm.h +++ b/drivers/misc/lkdtm/lkdtm.h @@ -22,6 +22,9 @@ void lkdtm_SOFTLOCKUP(void); void lkdtm_HARDLOCKUP(void); void lkdtm_SPINLOCKUP(void); void lkdtm_HUNG_TASK(void); +void lkdtm_OVERFLOW_SIGNED(void); +void lkdtm_OVERFLOW_UNSIGNED(void); +void lkdtm_ARRAY_BOUNDS(void); void lkdtm_CORRUPT_LIST_ADD(void); void lkdtm_CORRUPT_LIST_DEL(void); void lkdtm_CORRUPT_USER_DS(void);