From patchwork Wed Dec 11 18:40:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Catalin Marinas X-Patchwork-Id: 11285961 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 39A2C14B7 for ; Wed, 11 Dec 2019 18:44:39 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id DF60920663 for ; Wed, 11 Dec 2019 18:44:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="nMs/z2LO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DF60920663 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=cGgA5u4tV3FK6M7edreVg8mtwIsoY7gAdEZcj5sjUjE=; b=nMs/z2LOA6WDYe l4it3SOTvpuI4mbUrqVwGzdMl7UeBFLWDMc/816I+nJYiEjugWn8eVjVuDFCtE7bk9y3h4G3y9+lT wB2wSqbKph4H5flVtRn/MJsPcME7LK71PqBHDd2eVgSXyLVIyDxFupbqc62EvXG4e7p+0WioVoMot M/TJCP8PTCmadnIj7RbAqNui4R1/m+vfwYii0jfF7CU9OBOv+EOvXOO39I+WWXz367zWNf9BfFRhz QxvJq61sxu0uLDB/t8LUV7H1mXvfNN0LRWIzcKx7hrhEAtjMaTuicXPg23PxvvS9pF5I4RBZekXne MO2lFq2VHap61WfMu8wA==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1if6yR-0006pv-Gu; Wed, 11 Dec 2019 18:44:35 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1if6v2-0003OE-DV for linux-arm-kernel@lists.infradead.org; Wed, 11 Dec 2019 18:41:06 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 48A84147A; Wed, 11 Dec 2019 10:41:04 -0800 (PST) Received: from arrakis.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id D3D583F6CF; Wed, 11 Dec 2019 10:41:02 -0800 (PST) From: Catalin Marinas To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 16/22] mm: Introduce arch_validate_flags() Date: Wed, 11 Dec 2019 18:40:21 +0000 Message-Id: <20191211184027.20130-17-catalin.marinas@arm.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191211184027.20130-1-catalin.marinas@arm.com> References: <20191211184027.20130-1-catalin.marinas@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191211_104104_523506_433137FC X-CRM114-Status: GOOD ( 12.09 ) X-Spam-Score: 0.0 (/) X-Spam-Report: SpamAssassin version 3.4.2 on bombadil.infradead.org summary: Content analysis details: (0.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [217.140.110.172 listed in list.dnswl.org] 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.0 SPF_PASS SPF: sender matches SPF record X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-arch@vger.kernel.org, Richard Earnshaw , Szabolcs Nagy , Marc Zyngier , Kevin Brodsky , linux-mm@kvack.org, Andrey Konovalov , Vincenzo Frascino , Will Deacon Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org Similarly to arch_validate_prot() called from do_mprotect_pkey(), an architecture may need to sanity-check the new vm_flags. Define a dummy function always returning true. In addition to do_mprotect_pkey(), also invoke it from mmap_region() prior to updating vma->vm_page_prot to allow the architecture code to veto potentially inconsistent vm_flags. Signed-off-by: Catalin Marinas --- include/linux/mman.h | 13 +++++++++++++ mm/mmap.c | 9 +++++++++ mm/mprotect.c | 8 ++++++++ 3 files changed, 30 insertions(+) diff --git a/include/linux/mman.h b/include/linux/mman.h index c53b194c11a1..686fa6c98ce7 100644 --- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -103,6 +103,19 @@ static inline bool arch_validate_prot(unsigned long prot, unsigned long addr) #define arch_validate_prot arch_validate_prot #endif +#ifndef arch_validate_flags +/* + * This is called from mprotect() with the updated vma->vm_flags. + * + * Returns true if the VM_* flags are valid. + */ +static inline bool arch_validate_flags(unsigned long flags) +{ + return true; +} +#define arch_validate_flags arch_validate_flags +#endif + /* * Optimisation macro. It is equivalent to: * (x & bit1) ? bit2 : 0 diff --git a/mm/mmap.c b/mm/mmap.c index 9c648524e4dc..433355c5bdf1 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1804,6 +1804,15 @@ unsigned long mmap_region(struct file *file, unsigned long addr, vma_set_anonymous(vma); } + /* Allow architectures to sanity-check the vm_flags */ + if (!arch_validate_flags(vma->vm_flags)) { + error = -EINVAL; + if (file) + goto unmap_and_free_vma; + else + goto free_vma; + } + vma_link(mm, vma, prev, rb_link, rb_parent); /* Once vma denies write, undo our temporary denial count */ if (file) { diff --git a/mm/mprotect.c b/mm/mprotect.c index 7a8e84f86831..787b071bcbfd 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -543,6 +543,14 @@ static int do_mprotect_pkey(unsigned long start, size_t len, goto out; } + /* + * Allow architectures to sanity-check the new flags. + */ + if (!arch_validate_flags(newflags)) { + error = -EINVAL; + goto out; + } + error = security_file_mprotect(vma, reqprot, prot); if (error) goto out;