From patchwork Wed Aug 17 00:20:29 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9285019 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id A6A8B60574 for ; Wed, 17 Aug 2016 00:21:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 98233287A6 for ; Wed, 17 Aug 2016 00:21:15 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8C927288A1; Wed, 17 Aug 2016 00:21:15 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id 5160A287A6 for ; Wed, 17 Aug 2016 00:21:14 +0000 (UTC) Received: (qmail 31936 invoked by uid 550); 17 Aug 2016 00:20:49 -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: Reply-To: kernel-hardening@lists.openwall.com Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 31786 invoked from network); 17 Aug 2016 00:20:46 -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=qKIvbFa6dxODt7Ceqse5h20wWewzIwoz9PvUVaZwbn4=; b=JkRTaIgu0briq7t6PaZTSW1KUdOfq1WrdREriGKe/sLIwPXRor/18AZnRGngmBsB0B 0DEluYQBwwamOh/odxnMHaqdwWjGlbsx6Ml/b/5RM/dbEJXVlYJDl0Cj8DdubN0pj/S8 rot9IUt2HNevDC2R/02q58zS5HjjlyAffRwgw= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=qKIvbFa6dxODt7Ceqse5h20wWewzIwoz9PvUVaZwbn4=; b=eP231iOwJhGnuL6rx/wUiNvi5Vi1aX8w0BdvYYub/voMz3NB0sosd7C2sO/mcDs5T1 y5+4IHXOGqdqlJIH2pOjWXQ5uqlOzzUF6D7kCS9uFLR3QvqreTiMj3YJWUAOySsABKit kGj1juMFg4ejQcIKHx7WqASGBIfP/mhLfQU8sdmhH6PV4GGvPMxgEVxMFtAaGTpdJWJB 99fh8DuBHE3mJq4qT4aPCj2dsLAZ2wfojvRC864jFxsCk57zVYAWL6ssRH4kX7ehkArl V8aHc3gAyHZg8tHfHPWAh46Kq5D29OCyMra1H032v0/Ee7rZGXYS4jd/1zdc28Ribj/3 hOvQ== X-Gm-Message-State: AEkoouvRkHqI0SV/GxqElw2crZeuwnQOvDo6EhwAusDpw76wWQkNEsjN15sF/YjrJxzsmA1G X-Received: by 10.98.192.12 with SMTP id x12mr8931730pff.54.1471393234561; Tue, 16 Aug 2016 17:20:34 -0700 (PDT) From: Kees Cook To: "Paul E . McKenney" Cc: Kees Cook , Laura Abbott , Steven Rostedt , Stephen Boyd , Daniel Micay , Joe Perches , Arnd Bergmann , Greg Kroah-Hartman , Josh Triplett , Mathieu Desnoyers , Lai Jiangshan , "Aneesh Kumar K.V" , "Kirill A. Shutemov" , Michael Ellerman , Dan Williams , Andrew Morton , Ingo Molnar , Thomas Gleixner , Josef Bacik , Andrey Ryabinin , Tejun Heo , Nikolay Aleksandrov , Dmitry Vyukov , linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com Date: Tue, 16 Aug 2016 17:20:29 -0700 Message-Id: <1471393229-27182-6-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1471393229-27182-1-git-send-email-keescook@chromium.org> References: <1471393229-27182-1-git-send-email-keescook@chromium.org> Subject: [kernel-hardening] [PATCH v2 5/5] lkdtm: Add tests for struct list corruption X-Virus-Scanned: ClamAV using ClamSMTP When building under CONFIG_DEBUG_LIST, list addition and removal will be sanity-checked. This validates that the check is working as expected by setting up classic corruption attacks against list manipulations, available with the new lkdtm tests CORRUPT_LIST_ADD and CORRUPT_LIST_DEL. Signed-off-by: Kees Cook --- drivers/misc/lkdtm.h | 2 ++ drivers/misc/lkdtm_bugs.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++ drivers/misc/lkdtm_core.c | 2 ++ 3 files changed, 72 insertions(+) diff --git a/drivers/misc/lkdtm.h b/drivers/misc/lkdtm.h index fdf954c2107f..cfa1039c62e7 100644 --- a/drivers/misc/lkdtm.h +++ b/drivers/misc/lkdtm.h @@ -21,6 +21,8 @@ void lkdtm_SPINLOCKUP(void); void lkdtm_HUNG_TASK(void); void lkdtm_ATOMIC_UNDERFLOW(void); void lkdtm_ATOMIC_OVERFLOW(void); +void lkdtm_CORRUPT_LIST_ADD(void); +void lkdtm_CORRUPT_LIST_DEL(void); /* lkdtm_heap.c */ void lkdtm_OVERWRITE_ALLOCATION(void); diff --git a/drivers/misc/lkdtm_bugs.c b/drivers/misc/lkdtm_bugs.c index 182ae1894b32..f336206d4b1f 100644 --- a/drivers/misc/lkdtm_bugs.c +++ b/drivers/misc/lkdtm_bugs.c @@ -5,8 +5,13 @@ * test source files. */ #include "lkdtm.h" +#include #include +struct lkdtm_list { + struct list_head node; +}; + /* * Make sure our attempts to over run the kernel stack doesn't trigger * a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we @@ -146,3 +151,66 @@ void lkdtm_ATOMIC_OVERFLOW(void) pr_info("attempting bad atomic overflow\n"); atomic_inc(&over); } + +void lkdtm_CORRUPT_LIST_ADD(void) +{ + /* + * Initially, an empty list via LIST_HEAD: + * test_head.next = &test_head + * test_head.prev = &test_head + */ + LIST_HEAD(test_head); + struct lkdtm_list good, bad; + void *target[2] = { }; + void *redirection = ⌖ + + pr_info("attempting good list addition\n"); + + /* + * Adding to the list performs these actions: + * test_head.next->prev = &good.node + * good.node.next = test_head.next + * good.node.prev = test_head + * test_head.next = good.node + */ + list_add(&good.node, &test_head); + + pr_info("attempting corrupted list addition\n"); + /* + * In simulating this "write what where" primitive, the "what" is + * the address of &bad.node, and the "where" is the address held + * by "redirection". + */ + test_head.next = redirection; + list_add(&bad.node, &test_head); + + if (target[0] == NULL && target[1] == NULL) + pr_err("Overwrite did not happen, but no BUG?!\n"); + else + pr_err("list_add() corruption not detected!\n"); +} + +void lkdtm_CORRUPT_LIST_DEL(void) +{ + LIST_HEAD(test_head); + struct lkdtm_list item; + void *target[2] = { }; + void *redirection = ⌖ + + list_add(&item.node, &test_head); + + pr_info("attempting good list removal\n"); + list_del(&item.node); + + pr_info("attempting corrupted list removal\n"); + list_add(&item.node, &test_head); + + /* As with the list_add() test above, this corrupts "next". */ + item.node.next = redirection; + list_del(&item.node); + + if (target[0] == NULL && target[1] == NULL) + pr_err("Overwrite did not happen, but no BUG?!\n"); + else + pr_err("list_del() corruption not detected!\n"); +} diff --git a/drivers/misc/lkdtm_core.c b/drivers/misc/lkdtm_core.c index f9154b8d67f6..7eeb71a75549 100644 --- a/drivers/misc/lkdtm_core.c +++ b/drivers/misc/lkdtm_core.c @@ -197,6 +197,8 @@ struct crashtype crashtypes[] = { CRASHTYPE(EXCEPTION), CRASHTYPE(LOOP), CRASHTYPE(OVERFLOW), + CRASHTYPE(CORRUPT_LIST_ADD), + CRASHTYPE(CORRUPT_LIST_DEL), CRASHTYPE(CORRUPT_STACK), CRASHTYPE(UNALIGNED_LOAD_STORE_WRITE), CRASHTYPE(OVERWRITE_ALLOCATION),