From patchwork Tue Apr 21 14:25:53 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Catalin Marinas X-Patchwork-Id: 11501637 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 CF47F1392 for ; Tue, 21 Apr 2020 14:30:53 +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 527A7206D4 for ; Tue, 21 Apr 2020 14:30:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Vy6YGXOv" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 527A7206D4 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=9y/wcDvwyPhrJ/Q7K2dK6o8cWwxkADZx7zIO6tks2Rc=; b=Vy6YGXOvGnGcCH Je9Qt76Nj5xFexkXjpbM1Pdxhj225eFkpAxNTjJoVXnFJCNwesF9kW1yjaGh98jzF42shqcrME6jp 3YT0WaI1mPhAak29Uvjr62BeOgBVzfugD5EtcQdS0sENUwTICjen5JrPtZHy9W3jadwBkzG/iHhcK vLj2csvyQ0OukNQvQ8DlLk8lticLw4kYv3Up/6uHQ2HfpofXWvDlDLooPWhUAQLWBV7HtvCF5YcM6 KuLLNxbWSssA7XWqHgB937vvt4iujLBVA1Xp7pGvQRd9OcvAW37Xi7JZM/NZ1r/Gw046BwMDB/DmJ 9EfW/jji/R/1sjFmvPmw==; 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 1jQtv9-0005lA-6d; Tue, 21 Apr 2020 14:30:43 +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 1jQtr9-0008HM-G5 for linux-arm-kernel@lists.infradead.org; Tue, 21 Apr 2020 14:26:37 +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 097C131B; Tue, 21 Apr 2020 07:26:35 -0700 (PDT) Received: from localhost.localdomain (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7A5283F68F; Tue, 21 Apr 2020 07:26:33 -0700 (PDT) From: Catalin Marinas To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v3 13/23] mm: Introduce arch_validate_flags() Date: Tue, 21 Apr 2020 15:25:53 +0100 Message-Id: <20200421142603.3894-14-catalin.marinas@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200421142603.3894-1-catalin.marinas@arm.com> References: <20200421142603.3894-1-catalin.marinas@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200421_072635_667651_1900D607 X-CRM114-Status: GOOD ( 12.38 ) X-Spam-Score: -2.3 (--) X-Spam-Report: SpamAssassin version 3.4.4 on bombadil.infradead.org summary: Content analysis details: (-2.3 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at https://www.dnswl.org/, medium trust [217.140.110.172 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an 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 , Andrey Konovalov , Kevin Brodsky , Peter Collingbourne , linux-mm@kvack.org, 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 Cc: Will Deacon --- Notes: v2: - Some comments updated. include/linux/mman.h | 13 +++++++++++++ mm/mmap.c | 9 +++++++++ mm/mprotect.c | 6 ++++++ 3 files changed, 28 insertions(+) diff --git a/include/linux/mman.h b/include/linux/mman.h index 15c1162b9d65..09dd414b81b6 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 mmap() and 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 f609e9ec4a25..d5fc93c2072e 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1792,6 +1792,15 @@ 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 494192ca954b..04b1d2cf0e74 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -603,6 +603,12 @@ 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;