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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, 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 20B88C32792 for ; Thu, 3 Oct 2019 16:37:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE5E920830 for ; Thu, 3 Oct 2019 16:37:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570120621; bh=CmtXy0D0yuXcEhN0X7903mDS0j4POCGAx1nqzYqdUeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=YWzMDm0xN4QWOa6DpG/3TGm5+PIwaWIaNK4zJrRf6V6n04Gh5+tXwdxwcppPzvQZL fBJcNkBoKW9eduYb7KKJzI70cskQV0E8z8YqGJ4FXlNBDGG7azStT+utillYMQ1Hij iW07fYJufLgSpI7Wu3I9mXCN7JrjreTNhdXI62ko= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391380AbfJCQg7 (ORCPT ); Thu, 3 Oct 2019 12:36:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:46256 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404501AbfJCQg4 (ORCPT ); Thu, 3 Oct 2019 12:36:56 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 7CA3720830; Thu, 3 Oct 2019 16:36:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1570120616; bh=CmtXy0D0yuXcEhN0X7903mDS0j4POCGAx1nqzYqdUeI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S7Krhuim0Zi41s2CLz9+cy2fC9XvW3IsvC4cofChvTLgXiJ1CUu4gn2twKaywlJlC NbOBK2P+k596Ey25ga8LbRiKtsfMAr7ybkmfU2xocFSklqwvv2EE9ZPUUVBXsG5e/f Gov4PfIPpNt09hP3XZusldF4mzhzihz0aLCeH5zY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Kees Cook , Linus Torvalds , Richard Kojedzinszky Subject: [PATCH 5.2 250/313] binfmt_elf: Do not move brk for INTERP-less ET_EXEC Date: Thu, 3 Oct 2019 17:53:48 +0200 Message-Id: <20191003154557.675459805@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191003154533.590915454@linuxfoundation.org> References: <20191003154533.590915454@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Kees Cook commit 7be3cb019db1cbd5fd5ffe6d64a23fefa4b6f229 upstream. When brk was moved for binaries without an interpreter, it should have been limited to ET_DYN only. In other words, the special case was an ET_DYN that lacks an INTERP, not just an executable that lacks INTERP. The bug manifested for giant static executables, where the brk would end up in the middle of the text area on 32-bit architectures. Reported-and-tested-by: Richard Kojedzinszky Fixes: bbdc6076d2e5 ("binfmt_elf: move brk out of mmap when doing direct loader exec") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- fs/binfmt_elf.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -1142,7 +1142,8 @@ out_free_interp: * (since it grows up, and may collide early with the stack * growing down), and into the unused ELF_ET_DYN_BASE region. */ - if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) && !interpreter) + if (IS_ENABLED(CONFIG_ARCH_HAS_ELF_RANDOMIZE) && + loc->elf_ex.e_type == ET_DYN && !interpreter) current->mm->brk = current->mm->start_brk = ELF_ET_DYN_BASE;