From patchwork Thu Nov 21 18:15:19 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11256795 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 537A9930 for ; Thu, 21 Nov 2019 18:16:06 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id A8B50206CB for ; Thu, 21 Nov 2019 18:16:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="AUOvfPWM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A8B50206CB 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-17417-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 30406 invoked by uid 550); 21 Nov 2019 18:15:45 -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 30208 invoked from network); 21 Nov 2019 18:15:43 -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=AUOvfPWMFq4respwzA0a7ruKECsyXNc2uFyzNEbqSnofRJKhfkixrJJ0M+DfKvrJxy OyeHQu1ARk/u7CyYkgiVLfxU9mPHkRpyTfW0lX3RFQNpV30KQ8mB5qjnK2AK8Db4f/BI V7fIe1AlaR3RbttdT03b1f/4luN3yqTzQl3gs= 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=Lo665/+i/yLVHwEwpbeMeRmPEwOSMrYCWh/oOdksNHJ88mn16bZT2wW4xgNeFmPnY4 GpNagMCEVk9U1qzlnQsAYR3OCTW+jQ4oWuBKiE+Envl3fsVCzcuIWiFXbtuxgIZm3uBF 7OqrvJlSllQdaq6LpT1ckS0K11uFWYwCWPd/Sxr3j8tujil4cZRA+Lse1ig68fA+AQ0V cUg5CP9vUp1hxlNhGYBzSwcHgaltQdwo96bf7TcFdHNN994PU0XbQooI/+3XWeWGBMAJ MKI5PKrfhX2+QlBXxQcVNJF7tYEOFnrlB76zd75tqPyu/uAamdEGyri1Am3ZmDBbc0G0 nJ1Q== X-Gm-Message-State: APjAAAUulcKv30ZN4sQVaADrD5yXk4agCfcgDBYcCTUc7aZv24LErBR1 RwbK7teiD7RPyInpzo1xHl7mnw== X-Google-Smtp-Source: APXvYqwYaxQm1EsXEJba84FDgOq6w11jd48NYQ2iAFZdb0g9WHYhwZWRGHcjD+YTLE62j1VjOIgDnw== X-Received: by 2002:a17:90a:3d01:: with SMTP id h1mr13598717pjc.15.1574360131608; Thu, 21 Nov 2019 10:15:31 -0800 (PST) From: Kees Cook To: Andrew Morton Cc: Kees Cook , Andrey Ryabinin , Elena Petrova , Alexander Potapenko , Dmitry Vyukov , Linus Torvalds , Dan Carpenter , "Gustavo A. R. Silva" , Arnd Bergmann , Ard Biesheuvel , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com Subject: [PATCH v2 3/3] lkdtm/bugs: Add arithmetic overflow and array bounds checks Date: Thu, 21 Nov 2019 10:15:19 -0800 Message-Id: <20191121181519.28637-4-keescook@chromium.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20191121181519.28637-1-keescook@chromium.org> References: <20191121181519.28637-1-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);