From patchwork Thu Feb 27 19:35:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11409571 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 60E8B159A for ; Thu, 27 Feb 2020 19:36:12 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id BD652222C2 for ; Thu, 27 Feb 2020 19:36:10 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="U18RVdaW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD652222C2 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-17988-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 1859 invoked by uid 550); 27 Feb 2020 19:35:40 -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 1760 invoked from network); 27 Feb 2020 19:35:37 -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 :mime-version:content-transfer-encoding; bh=tZTI1WKOfKcUGuqkPLx5fh8/0duDs7Ezr+5qHoGz4tY=; b=U18RVdaWlP4fBhZgQ7gfvBZ661edo3X9oUFSv45hHr9vetX28ZNvck46LUZ1rbgFl7 CoC4XHpp5cC7LAS3bYtkiJL7toH48S68r6LeXzb4rPgznn2+AxmV9w7kxkJPj9fN2INY Amg3+QBFjZeomIWu5Uc7552gBpvlzUK6BPO/k= 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:mime-version:content-transfer-encoding; bh=tZTI1WKOfKcUGuqkPLx5fh8/0duDs7Ezr+5qHoGz4tY=; b=MjDJbyWHSlrHD1rply1bi6OB6kM21OY7V8ERoBDQ7/B52kfqz2+84GzWKqfje8jwv5 /G8Xt58rwZg7zaJt2aQxQ4UlEhlI2JgGhgbRI+qX0kHkGpWn/Mr02Hd4cr6BK3uTsHAa rd6w88FZR+s+q+BG//N7jFz/0NTGbV7lLDUjX7LBcfdhp7m0lY3FTJ0ASTF+mnUbnzlX 5bwN6r7KcsK8Gs75QRyJCVGiBrgDRiKw1bOXzNdy5tVk7XIxZE8UF+MRAlP35CSA/rWG PUG8HV9wZlGJtgRWLwK9Uv0KXyJgbRwBBQt/Ode0N5XmATMRN3CTjkSCvb0mfWZXhx+H 1s4Q== X-Gm-Message-State: APjAAAV+G1R9PBgKFZRTXWC20ySjgAfwC/MqRetEk5hfQSss0+kCdHST VH0Qa2/sMNZTlzdI/v3E0D2vcA== X-Google-Smtp-Source: APXvYqxyCvij60VoJLTsJE+/xAjIsKAshftPcvHqagxU4eIhmZpMwxKx52I39qHK7Pkm7LLOl0iliA== X-Received: by 2002:a65:668c:: with SMTP id b12mr914117pgw.14.1582832125520; Thu, 27 Feb 2020 11:35:25 -0800 (PST) From: Kees Cook To: Andrew Morton Cc: Kees Cook , Dmitry Vyukov , Andrey Ryabinin , Elena Petrova , Andrey Konovalov , Alexander Potapenko , Dan Carpenter , "Gustavo A. R. Silva" , Arnd Bergmann , Ard Biesheuvel , kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com, syzkaller@googlegroups.com Subject: [PATCH v5 3/6] lkdtm/bugs: Add arithmetic overflow and array bounds checks Date: Thu, 27 Feb 2020 11:35:13 -0800 Message-Id: <20200227193516.32566-4-keescook@chromium.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200227193516.32566-1-keescook@chromium.org> References: <20200227193516.32566-1-keescook@chromium.org> MIME-Version: 1.0 Adds LKDTM tests for arithmetic overflow (both signed and unsigned), as well as array bounds checking. Signed-off-by: Kees Cook Acked-by: Dmitry Vyukov --- 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 de87693cf557..e4c61ffea35c 100644 --- a/drivers/misc/lkdtm/bugs.c +++ b/drivers/misc/lkdtm/bugs.c @@ -11,6 +11,7 @@ #include #include #include +#include #ifdef CONFIG_X86_32 #include @@ -175,6 +176,80 @@ 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; + volatile 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 ee0d6e721441..2e04719b503c 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 c56d23e37643..8391081c6f13 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);