From patchwork Wed Feb 13 22:41:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Igor Stoppa X-Patchwork-Id: 10811015 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id A262413A4 for ; Wed, 13 Feb 2019 22:42:28 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 924762E5BD for ; Wed, 13 Feb 2019 22:42:28 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 85F932E5BF; Wed, 13 Feb 2019 22:42:28 +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=-3.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EBB8D2E5C4 for ; Wed, 13 Feb 2019 22:42:27 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3A4768E0009; Wed, 13 Feb 2019 17:42:26 -0500 (EST) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 3534B8E0001; Wed, 13 Feb 2019 17:42:26 -0500 (EST) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 243A78E0009; Wed, 13 Feb 2019 17:42:26 -0500 (EST) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from mail-wr1-f72.google.com (mail-wr1-f72.google.com [209.85.221.72]) by kanga.kvack.org (Postfix) with ESMTP id BCFEF8E0001 for ; Wed, 13 Feb 2019 17:42:25 -0500 (EST) Received: by mail-wr1-f72.google.com with SMTP id e2so1420429wrv.16 for ; Wed, 13 Feb 2019 14:42:25 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:from:to:cc:subject:date :message-id:in-reply-to:references:reply-to:mime-version :content-transfer-encoding; bh=FDryqu5ur4j9ePg/wc9MnpTPYVkBg8AjJFLLJs3gfA8=; b=hoSKbBtfpbj9OHt5963nQzgnb0bv0uVt0FMtKRj+smqQjzX/jfxplOdpNbFITsJyz4 AFT6o8vU7Nk1U2tv9kfl6b/XzyN9O8IQj26bSNqsqDWcw3lBrNP+qmBfIZx2RA5+hgGx KSqiOQiwg+QV1PuTJo8LIGDcEdo+ojtLQ+iTmb2YfNS7dBMPwtl8yTAdevXvEnDDLmav Q15ITG9obGLFXcHkNGs3s0pzPR3K44yUu37U/w/ylSGM+GQtD7FkUhFQR/MvEl4yNr0T x/08bIBpvePWbcZ+F4qFixL3BrpROE4uIon1Qpje+x6RAHaHepUHXXiOOPiYChoKuHIC NKRw== X-Gm-Message-State: AHQUAuYbVhoL00Blsdb8sJO/B/cb6k/qpZLjBwJpBhC69+tXP0jf8dTr cInYbF8O9UyAW2cQTcP1uXXE9R9+YVxwcBWR+Im01wSShKY3ZedSY9mdtAnvGTp3v+YqMvvMDrW QgvC5oiK6tR/ZVjrzA3hhUnal9KFbqS3gUuj1G5NLFj7TWhYm8FwOit7v5jIrxwnyo7TIn+gur/ UaeHvhVHV/CWX5gsHoYLryMP0XAkm09yNSUH/rptjKS/MzFqBve6pFX7OXI2LRYK+EvTcs6D6Jb 0HQsL+CRbuCfJB6S8Lm5jxeAd7CiD9aQLb6GfYO127X/ddZSuEEOex2jL4xwtyOBKqbtPfSTISb BPHjCnrgK3rYHfU4xubXxSJujZEPLsBqME8igIRoDKNArAeu3/b0PraxsQ29xe1rFZuy/Mi02iI s X-Received: by 2002:adf:f410:: with SMTP id g16mr319589wro.246.1550097745286; Wed, 13 Feb 2019 14:42:25 -0800 (PST) X-Received: by 2002:adf:f410:: with SMTP id g16mr319531wro.246.1550097743982; Wed, 13 Feb 2019 14:42:23 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1550097743; cv=none; d=google.com; s=arc-20160816; b=aWhETM7947fM7ipKcGBSlAgCgsvBV9Kp1qYqjCX9D9snLKM9KwmNaGYiKqtowNODYG dAUvQi5c04ztSX/qie+bfkaI1K+HK9Wr5ZsWkugPBLxBs84t14hQbHzkt/rn0t5NzoNb ldcUv8mhDUNQhhsTIsddxxA2ZPxYZKrNL7g5KA8/132lQBI6UnIVI3+zW7SWsv/wnvFh tQf5UBtjfPC0UZTu6fkqD/qhB3q85aJcDQnvODqIgKDlIYu0iim+rO8WIyvRLQmwv3eJ /UT3HFxrBkRySAe6UDDKxncXyMzm2D2vtxQMrZPYNvD1LaW9vk6BB4w6XmB4TDHwBVcq QJvw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:mime-version:reply-to:references :in-reply-to:message-id:date:subject:cc:to:from:dkim-signature; bh=FDryqu5ur4j9ePg/wc9MnpTPYVkBg8AjJFLLJs3gfA8=; b=qnxBd0ErdEM3BjZ9VmLpuq54PGx2it88wh0d5YyKfL162GIJ+F2Sn9d2MATuUFSvmg z9WEOX7hHxM9rEQDwyKF3LzJg0JEuO5GnPWS6Eq3swBJADnK0gNnTz2JqxamrEialnUy ZKjdUBWID1H/o1DRYAFcpDvFM527JFms9Kf3CWLprrHZrmmBuS8lDNw7SpI56aANWlIR YqepDchEntkSvt13mdMRAUA2zbOuKsq8T+1j1O708t3/c7RKMAW+Xa/bHFTlG20WaNLs lZm8hIjLJm620xpzH7IhLX7kNmSgylfyXSxIE2Ux0eFvMxnrZwkznSHZxT2uCvL0dUZa lJ1w== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=NjIzVPkQ; spf=pass (google.com: domain of igor.stoppa@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=igor.stoppa@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id t8sor377761wmh.15.2019.02.13.14.42.23 for (Google Transport Security); Wed, 13 Feb 2019 14:42:23 -0800 (PST) Received-SPF: pass (google.com: domain of igor.stoppa@gmail.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=NjIzVPkQ; spf=pass (google.com: domain of igor.stoppa@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=igor.stoppa@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references:reply-to :mime-version:content-transfer-encoding; bh=FDryqu5ur4j9ePg/wc9MnpTPYVkBg8AjJFLLJs3gfA8=; b=NjIzVPkQI+bCcLNEI/Rt4U85tu0DGaKik0uQCOMXvSEkO/SvlHDTcAU8+IhLk21y1p 5m+FNp4iAWRrJ/k/DDDQZG8GEE1PO9QmTNuEZj9sZ3t8GOVxkaHS88LjJhq6BKQ7N9X3 FJu9x7w0j1lXKAVEa9NaOLOiDSwyj28NVgD1R/mi4Ij/muEfi9+4T/7X6PO8M08gwtT4 aaJwB93WJNH0Lk9jcLkQo1ju6chbGRcgdS0TIt45lL7EReQ2hPmGRvbjzBEH7IuKbkQK PTBJS9E+bupu40oKgPBcvq9VxB11GBhj6qIU7b2yqA1Ep6uVGLC5RY2njYXlBvxDI91M RhlQ== X-Google-Smtp-Source: AHgI3Ia10COWxjNMWWeGUZ4kyfPoLmhHvf/GKRNqfO/0o20+P2q+df+RyfuyEETkMZNIJGOmGU8VSw== X-Received: by 2002:a1c:e086:: with SMTP id x128mr325384wmg.10.1550097743522; Wed, 13 Feb 2019 14:42:23 -0800 (PST) Received: from localhost.localdomain ([91.75.74.250]) by smtp.gmail.com with ESMTPSA id f196sm780810wme.36.2019.02.13.14.42.20 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 13 Feb 2019 14:42:22 -0800 (PST) From: Igor Stoppa X-Google-Original-From: Igor Stoppa To: Cc: Igor Stoppa , Andy Lutomirski , Nadav Amit , Matthew Wilcox , Peter Zijlstra , Kees Cook , Dave Hansen , Mimi Zohar , Thiago Jung Bauermann , Ahmed Soliman , linux-integrity@vger.kernel.org, kernel-hardening@lists.openwall.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [RFC PATCH v5 08/12] __wr_after_init: lkdtm test Date: Thu, 14 Feb 2019 00:41:37 +0200 Message-Id: X-Mailer: git-send-email 2.19.1 In-Reply-To: References: Reply-To: Igor Stoppa MIME-Version: 1.0 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: X-Virus-Scanned: ClamAV using ClamSMTP Verify that trying to modify a variable with the __wr_after_init attribute will cause a crash. Signed-off-by: Igor Stoppa CC: Andy Lutomirski CC: Nadav Amit CC: Matthew Wilcox CC: Peter Zijlstra CC: Kees Cook CC: Dave Hansen CC: Mimi Zohar CC: Thiago Jung Bauermann CC: Ahmed Soliman CC: linux-integrity@vger.kernel.org CC: kernel-hardening@lists.openwall.com CC: linux-mm@kvack.org CC: linux-kernel@vger.kernel.org --- drivers/misc/lkdtm/core.c | 3 +++ drivers/misc/lkdtm/lkdtm.h | 3 +++ drivers/misc/lkdtm/perms.c | 29 +++++++++++++++++++++++++++++ 3 files changed, 35 insertions(+) diff --git a/drivers/misc/lkdtm/core.c b/drivers/misc/lkdtm/core.c index 2837dc77478e..73c34b17c433 100644 --- a/drivers/misc/lkdtm/core.c +++ b/drivers/misc/lkdtm/core.c @@ -155,6 +155,9 @@ static const struct crashtype crashtypes[] = { CRASHTYPE(ACCESS_USERSPACE), CRASHTYPE(WRITE_RO), CRASHTYPE(WRITE_RO_AFTER_INIT), +#ifdef CONFIG_PRMEM + CRASHTYPE(WRITE_WR_AFTER_INIT), +#endif CRASHTYPE(WRITE_KERN), CRASHTYPE(REFCOUNT_INC_OVERFLOW), CRASHTYPE(REFCOUNT_ADD_OVERFLOW), diff --git a/drivers/misc/lkdtm/lkdtm.h b/drivers/misc/lkdtm/lkdtm.h index 3c6fd327e166..abba2f52ffa6 100644 --- a/drivers/misc/lkdtm/lkdtm.h +++ b/drivers/misc/lkdtm/lkdtm.h @@ -38,6 +38,9 @@ void lkdtm_READ_BUDDY_AFTER_FREE(void); void __init lkdtm_perms_init(void); void lkdtm_WRITE_RO(void); void lkdtm_WRITE_RO_AFTER_INIT(void); +#ifdef CONFIG_PRMEM +void lkdtm_WRITE_WR_AFTER_INIT(void); +#endif void lkdtm_WRITE_KERN(void); void lkdtm_EXEC_DATA(void); void lkdtm_EXEC_STACK(void); diff --git a/drivers/misc/lkdtm/perms.c b/drivers/misc/lkdtm/perms.c index 53b85c9d16b8..f681730aa652 100644 --- a/drivers/misc/lkdtm/perms.c +++ b/drivers/misc/lkdtm/perms.c @@ -9,6 +9,7 @@ #include #include #include +#include #include /* Whether or not to fill the target memory area with do_nothing(). */ @@ -27,6 +28,10 @@ static const unsigned long rodata = 0xAA55AA55; /* This is marked __ro_after_init, so it should ultimately be .rodata. */ static unsigned long ro_after_init __ro_after_init = 0x55AA5500; +/* This is marked __wr_after_init, so it should be in .rodata. */ +static +unsigned long wr_after_init __wr_after_init = 0x55AA5500; + /* * This just returns to the caller. It is designed to be copied into * non-executable memory regions. @@ -104,6 +109,28 @@ void lkdtm_WRITE_RO_AFTER_INIT(void) *ptr ^= 0xabcd1234; } +#ifdef CONFIG_PRMEM + +void lkdtm_WRITE_WR_AFTER_INIT(void) +{ + unsigned long *ptr = &wr_after_init; + + /* + * Verify we were written to during init. Since an Oops + * is considered a "success", a failure is to just skip the + * real test. + */ + if ((*ptr & 0xAA) != 0xAA) { + pr_info("%p was NOT written during init!?\n", ptr); + return; + } + + pr_info("attempting bad wr_after_init write at %p\n", ptr); + *ptr ^= 0xabcd1234; +} + +#endif + void lkdtm_WRITE_KERN(void) { size_t size; @@ -200,4 +227,6 @@ void __init lkdtm_perms_init(void) /* Make sure we can write to __ro_after_init values during __init */ ro_after_init |= 0xAA; + /* Make sure we can write to __wr_after_init during __init */ + wr_after_init |= 0xAA; }