From patchwork Thu Jun 22 18:06:30 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 9805055 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C0F2360329 for ; Thu, 22 Jun 2017 18:06:56 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B8B9C2870B for ; Thu, 22 Jun 2017 18:06:56 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AB57528713; Thu, 22 Jun 2017 18:06:56 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.1 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED,T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.wl.linuxfoundation.org (Postfix) with SMTP id DE2722870B for ; Thu, 22 Jun 2017 18:06:55 +0000 (UTC) Received: (qmail 11347 invoked by uid 550); 22 Jun 2017 18:06:52 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 11326 invoked from network); 22 Jun 2017 18:06:52 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=h5WUZCIQPXerr5AgpWaB3BqLW06FzOAk1CMhI+LBxsw=; b=QeRkW8Z+n9q5W6OIlI6dcUIbvm3lNYbU8QY2nTiPPojep3IOTGz4d9jefF5FMKdf10 PqKkEXScAxqokztoaFa0+RcJR3zoAoe5C0FegLhoA6o0wFEGsoBJDzXaaCY3EO+Iy4+h JmxcFrxHOUIVMlDEPpGE9qztoLRRCY8ePSqoM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=h5WUZCIQPXerr5AgpWaB3BqLW06FzOAk1CMhI+LBxsw=; b=SA4BJxZKzDrE3lnJd7A1Prl1dQDfKBrYeOMrNK21uczvrVprh4WOS6CLI0/CR5CIK3 SHWhv+B9upu5Vt38+R2NaNO+iWJHZ340LchpCi+CPdmJjD6ZffmdcrBZXpTdQa4V8yiS VWON2F16MVApwTKR2UYS5/mLKnrI0G4+ws469zJa8P8sgDJSO9PDaFH6hjHiPBQhnEB3 Ry5WsNE9sx2RycQu+jYkUNiDB069+u0YxNwhGQ/G5yuxp4iMunwCyXChttZ8G8wkpn9/ PGWzneVFk6WxiASwnyqgtjaD41mHY297Tb03Gg8glpuxgZS7hX/5p150UpAFMW7wPv/A cnhA== X-Gm-Message-State: AKS2vOy4avYqkxtvNve1FuYiAmJkGbGd6PYDqatJJ7BmAn5YUI6zCGxc ImQ2RkDIk4IePFZh X-Received: by 10.84.128.68 with SMTP id 62mr4371478pla.184.1498154800160; Thu, 22 Jun 2017 11:06:40 -0700 (PDT) From: Kees Cook To: Andrew Morton Cc: Kees Cook , Russell King , Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Martin Schwidefsky , Heiko Carstens , James Hogan , Pratyush Anand , Ingo Molnar , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, kernel-hardening@lists.openwall.com Date: Thu, 22 Jun 2017 11:06:30 -0700 Message-Id: <1498154792-49952-3-git-send-email-keescook@chromium.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1498154792-49952-1-git-send-email-keescook@chromium.org> References: <1498154792-49952-1-git-send-email-keescook@chromium.org> Subject: [kernel-hardening] [PATCH 2/4] arm64: Reduce ELF_ET_DYN_BASE X-Virus-Scanned: ClamAV using ClamSMTP Now that explicitly executed loaders are loaded in the mmap region, position PIE binaries lower in the address space to avoid possible collisions with mmap or stack regions. For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit address space for 32-bit pointers. Signed-off-by: Kees Cook --- arch/arm64/include/asm/elf.h | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/elf.h b/arch/arm64/include/asm/elf.h index 5d1700425efe..f742af8f7c42 100644 --- a/arch/arm64/include/asm/elf.h +++ b/arch/arm64/include/asm/elf.h @@ -113,12 +113,13 @@ #define ELF_EXEC_PAGESIZE PAGE_SIZE /* - * This is the location that an ET_DYN program is loaded if exec'ed. Typical - * use of this is to invoke "./ld.so someprog" to test out a new version of - * the loader. We need to make sure that it is out of the way of the program - * that it will "exec", and that there is sufficient room for the brk. + * This is the base location for PIE (ET_DYN with INTERP) loads. On + * 64-bit, this is raised to 4GB to leave the entire 32-bit address + * space open for things that want to use the area for 32-bit pointers. */ -#define ELF_ET_DYN_BASE (2 * TASK_SIZE_64 / 3) +#define ELF_ET_DYN_BASE (test_thread_flag(TIF_32BIT) ? \ + 0x000400000UL : \ + 0x100000000UL) #ifndef __ASSEMBLY__ @@ -173,8 +174,6 @@ extern int arch_setup_additional_pages(struct linux_binprm *bprm, #ifdef CONFIG_COMPAT -#define COMPAT_ELF_ET_DYN_BASE (2 * TASK_SIZE_32 / 3) - /* AArch32 registers. */ #define COMPAT_ELF_NGREG 18 typedef unsigned int compat_elf_greg_t;