From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AC61AC2BA80 for ; Tue, 7 Apr 2020 03:12:37 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6977020716 for ; Tue, 7 Apr 2020 03:12:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="0xrVIbXM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6977020716 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 1C4C68E00A7; Mon, 6 Apr 2020 23:12:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 175498E0062; Mon, 6 Apr 2020 23:12:37 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 08BDB8E00A7; Mon, 6 Apr 2020 23:12:37 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0145.hostedemail.com [216.40.44.145]) by kanga.kvack.org (Postfix) with ESMTP id E303D8E0062 for ; Mon, 6 Apr 2020 23:12:36 -0400 (EDT) Received: from smtpin04.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id B6584A8CF for ; Tue, 7 Apr 2020 03:12:36 +0000 (UTC) X-FDA: 76679586312.04.oven57_16c2b3ad04519 X-HE-Tag: oven57_16c2b3ad04519 X-Filterd-Recvd-Size: 5620 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf22.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Apr 2020 03:12:36 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 261452082D; Tue, 7 Apr 2020 03:12:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586229155; bh=ZJiCkM3FSkxdyVn6PWzgXHA4p0NINczqFEfY2vvCwZY=; h=Date:From:To:Subject:In-Reply-To:From; b=0xrVIbXMsIApKoTPj+AlQ6JxwNKO8mOLUcSET+CqMp++IbOpc98zolZdxJvjYX+Kg kYLFpDBChcF+BzIV7mlwEigHfXBgIGW9MMhpECfDG4SRuUrKiMBvDxkpX11KVzvwYL 903ogEESLz0DtLC5l2JSEpeDrEqjpDDRcMVVPeVs= Date: Mon, 06 Apr 2020 20:12:34 -0700 From: Andrew Morton To: akpm@linux-foundation.org, andreyknvl@google.com, ard.biesheuvel@linaro.org, arnd@arndb.de, aryabinin@virtuozzo.com, dan.carpenter@oracle.com, dvyukov@google.com, glider@google.com, gustavo@embeddedor.com, keescook@chromium.org, lenaptr@google.com, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 160/166] drivers/misc/lkdtm/bugs.c: add arithmetic overflow and array bounds checks Message-ID: <20200407031234.-8O1JXJen%akpm@linux-foundation.org> In-Reply-To: <20200406200254.a69ebd9e08c4074e41ddebaf@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Kees Cook Subject: drivers/misc/lkdtm/bugs.c: add arithmetic overflow and array bounds checks Adds LKDTM tests for arithmetic overflow (both signed and unsigned), as well as array bounds checking. Link: http://lkml.kernel.org/r/20200227193516.32566-4-keescook@chromium.org Signed-off-by: Kees Cook Acked-by: Dmitry Vyukov Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: Dan Carpenter Cc: Elena Petrova Cc: "Gustavo A. R. Silva" Signed-off-by: Andrew Morton --- drivers/misc/lkdtm/bugs.c | 75 +++++++++++++++++++++++++++++++++++ drivers/misc/lkdtm/core.c | 3 + drivers/misc/lkdtm/lkdtm.h | 3 + 3 files changed, 81 insertions(+) --- a/drivers/misc/lkdtm/bugs.c~lkdtm-bugs-add-arithmetic-overflow-and-array-bounds-checks +++ a/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) { /* --- a/drivers/misc/lkdtm/core.c~lkdtm-bugs-add-arithmetic-overflow-and-array-bounds-checks +++ a/drivers/misc/lkdtm/core.c @@ -130,6 +130,9 @@ 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), --- a/drivers/misc/lkdtm/lkdtm.h~lkdtm-bugs-add-arithmetic-overflow-and-array-bounds-checks +++ a/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); _