From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 61043C677D4 for ; Mon, 8 Oct 2018 18:34:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 246BD2145D for ; Mon, 8 Oct 2018 18:34:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ty1VCvpm" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 246BD2145D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728028AbeJIBr4 (ORCPT ); Mon, 8 Oct 2018 21:47:56 -0400 Received: from mail.kernel.org ([198.145.29.99]:59672 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726646AbeJIBrz (ORCPT ); Mon, 8 Oct 2018 21:47:55 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 82AA32145D; Mon, 8 Oct 2018 18:34:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539023693; bh=bMpUZJzIdERSsL/hR46xAO9pJs8p7SItCZKTv6Jym8g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ty1VCvpmutH/BoTk2Tj8pEtAzAjnNzBIqZDL1RhLCmaYPn7F/bHKR1WnygKFutxMh J0lFHZ+gzJ5usS9yhVFyZdbGsYejJbBWsDOj2osYu6WVozKYJjGMgEhcsyE5TTBf6D 8Cd5LcwD4NsWFLDQQhfuvEfb9KnrqyWiCFV87E5g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Todd Kjos , devel@driverdev.osuosl.org, kernel-team@android.com, Joel Fernandes , Alistair Strachan , Martijn Coenen , Sasha Levin Subject: [PATCH 4.4 028/113] staging: android: ashmem: Fix mmap size validation Date: Mon, 8 Oct 2018 20:30:29 +0200 Message-Id: <20181008175532.231700050@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181008175530.864641368@linuxfoundation.org> References: <20181008175530.864641368@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Alistair Strachan [ Upstream commit 8632c614565d0c5fdde527889601c018e97b6384 ] The ashmem driver did not check that the size/offset of the vma passed to its .mmap() function was not larger than the ashmem object being mapped. This could cause mmap() to succeed, even though accessing parts of the mapping would later fail with a segmentation fault. Ensure an error is returned by the ashmem_mmap() function if the vma size is larger than the ashmem object size. This enables safer handling of the problem in userspace. Cc: Todd Kjos Cc: devel@driverdev.osuosl.org Cc: linux-kernel@vger.kernel.org Cc: kernel-team@android.com Cc: Joel Fernandes Signed-off-by: Alistair Strachan Acked-by: Joel Fernandes (Google) Reviewed-by: Martijn Coenen Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/staging/android/ashmem.c | 6 ++++++ 1 file changed, 6 insertions(+) --- a/drivers/staging/android/ashmem.c +++ b/drivers/staging/android/ashmem.c @@ -370,6 +370,12 @@ static int ashmem_mmap(struct file *file goto out; } + /* requested mapping size larger than object size */ + if (vma->vm_end - vma->vm_start > PAGE_ALIGN(asma->size)) { + ret = -EINVAL; + goto out; + } + /* requested protection bits must match our allowed protection mask */ if (unlikely((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask)) & calc_vm_prot_bits(PROT_MASK))) {