From patchwork Thu May 20 09:18:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 444508 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=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 876F8C433ED for ; Thu, 20 May 2021 09:46:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6CEF8619A8 for ; Thu, 20 May 2021 09:46:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233979AbhETJsE (ORCPT ); Thu, 20 May 2021 05:48:04 -0400 Received: from mail.kernel.org ([198.145.29.99]:47526 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233327AbhETJqG (ORCPT ); Thu, 20 May 2021 05:46:06 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A1781613E4; Thu, 20 May 2021 09:33:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621503228; bh=acPiaPB0erABLX7D+LJwy1ivSPdvufUDeiNNIB1qaPo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CXHiip3KPO8/sdVBBqwWJOFp68tE4qjcCBqlfDHUimPiF+4qeL56DHbCPNwG6r/sM PoxYNumbTNfEEOCTDgyVMFTCSdiEtJ1eIeHGMtX9rgAD73pXHh9x/EGEmZ9TzvgHhc 5z9YXrDmYt7BuaDXxdiggjbmwV5kCa5lxrxZtSqU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Daniel Vetter , Christoph Hellwig , Jessica Yu Subject: [PATCH 4.19 126/425] modules: inherit TAINT_PROPRIETARY_MODULE Date: Thu, 20 May 2021 11:18:15 +0200 Message-Id: <20210520092135.569490742@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210520092131.308959589@linuxfoundation.org> References: <20210520092131.308959589@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Christoph Hellwig commit 262e6ae7081df304fc625cf368d5c2cbba2bb991 upstream. If a TAINT_PROPRIETARY_MODULE exports symbol, inherit the taint flag for all modules importing these symbols, and don't allow loading symbols from TAINT_PROPRIETARY_MODULE modules if the module previously imported gplonly symbols. Add a anti-circumvention devices so people don't accidentally get themselves into trouble this way. Comment from Greg: "Ah, the proven-to-be-illegal "GPL Condom" defense :)" [jeyu: pr_info -> pr_err and pr_warn as per discussion] Link: http://lore.kernel.org/r/20200730162957.GA22469@lst.de Acked-by: Daniel Vetter Reviewed-by: Greg Kroah-Hartman Signed-off-by: Christoph Hellwig Signed-off-by: Jessica Yu Signed-off-by: Greg Kroah-Hartman --- include/linux/module.h | 1 + kernel/module.c | 27 +++++++++++++++++++++++++++ 2 files changed, 28 insertions(+) --- a/include/linux/module.h +++ b/include/linux/module.h @@ -359,6 +359,7 @@ struct module { unsigned int num_gpl_syms; const struct kernel_symbol *gpl_syms; const s32 *gpl_crcs; + bool using_gplonly_symbols; #ifdef CONFIG_UNUSED_SYMBOLS /* unused exported symbols. */ --- a/kernel/module.c +++ b/kernel/module.c @@ -1379,6 +1379,25 @@ static inline int same_magic(const char } #endif /* CONFIG_MODVERSIONS */ +static bool inherit_taint(struct module *mod, struct module *owner) +{ + if (!owner || !test_bit(TAINT_PROPRIETARY_MODULE, &owner->taints)) + return true; + + if (mod->using_gplonly_symbols) { + pr_err("%s: module using GPL-only symbols uses symbols from proprietary module %s.\n", + mod->name, owner->name); + return false; + } + + if (!test_bit(TAINT_PROPRIETARY_MODULE, &mod->taints)) { + pr_warn("%s: module uses symbols from proprietary module %s, inheriting taint.\n", + mod->name, owner->name); + set_bit(TAINT_PROPRIETARY_MODULE, &mod->taints); + } + return true; +} + /* Resolve a symbol for this module. I.e. if we find one, record usage. */ static const struct kernel_symbol *resolve_symbol(struct module *mod, const struct load_info *info, @@ -1403,6 +1422,14 @@ static const struct kernel_symbol *resol if (!sym) goto unlock; + if (license == GPL_ONLY) + mod->using_gplonly_symbols = true; + + if (!inherit_taint(mod, owner)) { + sym = NULL; + goto getname; + } + if (!check_version(info, name, mod, crc)) { sym = ERR_PTR(-EINVAL); goto getname;