From patchwork Tue Oct 23 21:34:56 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Igor Stoppa X-Patchwork-Id: 10653793 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 9D38814BB for ; Tue, 23 Oct 2018 21:38:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8A1772A4FA for ; Tue, 23 Oct 2018 21:38:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7E1722A4FD; Tue, 23 Oct 2018 21:38:04 +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=-5.0 required=2.0 tests=BAYES_00,DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED 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 A499C2A4FA for ; Tue, 23 Oct 2018 21:38:03 +0000 (UTC) Received: (qmail 14152 invoked by uid 550); 23 Oct 2018 21:36:22 -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 14109 invoked from network); 23 Oct 2018 21:36:21 -0000 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; bh=pGpymzbPbfMd0UY2O/PnMm8wYTcULxEjQ2M1QiLWUtQ=; b=etVVDgLocA4AjN+jxAXLRtXyFmyCKDXzTHMYFdYt+3XfgEEQNZehB6ZAubiCYjyvy0 C5GrkJFQrsxCI5EKgJi2Hh9syjIDh3WhQy6uGJipgVAL10O0CGT25+kfZsvBKU7+PtEs hAvdrW/iABvj+SaTIJ7FSEwZoqcJMNTTM7IyOYe6ITWgreOcX1fRhiAu4Aie0D3L+6Ah 0CL0xm+qqL4/H+nxwdF5UjsZq5aTf3xxTf9y0JGxopS2MHxBOZ9aDWIX2bUY5gqeHeBx G6gvyawpjFtqRLlCBActSQCZFme72y8lx8IlyO4u8ngtDN4fbCBBViLuXUbGABcQ4L4f JH8Q== 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:reply-to; bh=pGpymzbPbfMd0UY2O/PnMm8wYTcULxEjQ2M1QiLWUtQ=; b=U57GEP4AURbnpXcweYHb5qaEHW8fsAhUk7JR3owSHUZaknP0yzy3jtz4vyIfyJ5ue4 iYOiB4a44eUz+xYBa7RtsjRyR62yfQC8e0Ks3r8DTcPAhxhNncAfkZOa3eXSWtNSKoJv lra9ABd0DJwRdg94DQaBJmotp1qCYJsaCvKuqYNoM3osWx3igKWkdkKgvH8XxI8uqlss dyn5MXCqdoeqPn+9x8q5pQzHDLUjySdMPklEIJjfop1ryJijoh1VFySIjUhIFAIpl7vk dLNFP81yt30vRdcZSlthQUBbGdnv7FTz+Vtn/HUWcTKkP2epBKLsA/V+S1XzVdd0jMMG CIQw== X-Gm-Message-State: AGRZ1gKS8tr9bdLg447HGYNVTZMVrBpzL2RK3+kezUQQrQNu5o8eqJQS E8OnIMx8NzMChmwJxqqk33U= X-Google-Smtp-Source: AJdET5exRyQPy5ypGmiJjncDtEgR9KmCyJjS90PbVTRQUbcCgZs2pc0eSgkwJSERums9s+tyA2MWxw== X-Received: by 2002:a19:3809:: with SMTP id f9mr170930lfa.148.1540330570334; Tue, 23 Oct 2018 14:36:10 -0700 (PDT) From: Igor Stoppa X-Google-Original-From: Igor Stoppa To: Mimi Zohar , Kees Cook , Matthew Wilcox , Dave Chinner , James Morris , Michal Hocko , kernel-hardening@lists.openwall.com, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org Cc: igor.stoppa@huawei.com, Dave Hansen , Jonathan Corbet , Laura Abbott , Chris von Recklinghausen , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 09/17] prmem: hardened usercopy Date: Wed, 24 Oct 2018 00:34:56 +0300 Message-Id: <20181023213504.28905-10-igor.stoppa@huawei.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181023213504.28905-1-igor.stoppa@huawei.com> References: <20181023213504.28905-1-igor.stoppa@huawei.com> X-Virus-Scanned: ClamAV using ClamSMTP Prevent leaks of protected memory to userspace. The protection from overwrited from userspace is already available, once the memory is write protected. Signed-off-by: Igor Stoppa CC: Kees Cook CC: Chris von Recklinghausen CC: linux-mm@kvack.org CC: linux-kernel@vger.kernel.org --- include/linux/prmem.h | 24 ++++++++++++++++++++++++ mm/usercopy.c | 5 +++++ 2 files changed, 29 insertions(+) diff --git a/include/linux/prmem.h b/include/linux/prmem.h index cf713fc1c8bb..919d853ddc15 100644 --- a/include/linux/prmem.h +++ b/include/linux/prmem.h @@ -273,6 +273,30 @@ struct pmalloc_pool { uint8_t mode; }; +void __noreturn usercopy_abort(const char *name, const char *detail, + bool to_user, unsigned long offset, + unsigned long len); + +/** + * check_pmalloc_object() - helper for hardened usercopy + * @ptr: the beginning of the memory to check + * @n: the size of the memory to check + * @to_user: copy to userspace or from userspace + * + * If the check is ok, it will fall-through, otherwise it will abort. + * The function is inlined, to minimize the performance impact of the + * extra check that can end up on a hot path. + * Non-exhaustive micro benchmarking with QEMU x86_64 shows a reduction of + * the time spent in this fragment by 60%, when inlined. + */ +static inline +void check_pmalloc_object(const void *ptr, unsigned long n, bool to_user) +{ + if (unlikely(__is_wr_after_init(ptr, n) || __is_wr_pool(ptr, n))) + usercopy_abort("pmalloc", "accessing pmalloc obj", to_user, + (const unsigned long)ptr, n); +} + /* * The write rare functionality is fully implemented as __always_inline, * to prevent having an internal function call that is capable of modifying diff --git a/mm/usercopy.c b/mm/usercopy.c index 852eb4e53f06..a080dd37b684 100644 --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -22,8 +22,10 @@ #include #include #include +#include #include + /* * Checks if a given pointer and length is contained by the current * stack frame (if possible). @@ -284,6 +286,9 @@ void __check_object_size(const void *ptr, unsigned long n, bool to_user) /* Check for object in kernel to avoid text exposure. */ check_kernel_text_object((const unsigned long)ptr, n, to_user); + + /* Check if object is from a pmalloc chunk. */ + check_pmalloc_object(ptr, n, to_user); } EXPORT_SYMBOL(__check_object_size);