From patchwork Thu Mar 18 17:10:54 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12148765 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=-26.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 52EE2C433E9 for ; Thu, 18 Mar 2021 17:12:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2665264F30 for ; Thu, 18 Mar 2021 17:12:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232126AbhCRRLf (ORCPT ); Thu, 18 Mar 2021 13:11:35 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232257AbhCRRLQ (ORCPT ); Thu, 18 Mar 2021 13:11:16 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C4A7DC061763 for ; Thu, 18 Mar 2021 10:11:15 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id v92so6514752ybi.12 for ; Thu, 18 Mar 2021 10:11:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=SCzz0vkCTXCJ+hl1sGhlu0aynSHOxUfyv4GiVUi2UT8=; b=Qn2g5lLRvdKJvgzF43+LCRfbhyf/1XwO7VexN9MTAJ/y7/GXos2MZ6DPQ5+40SXSdr 3WUM1haHcbmP9fvJ5H0GP0vnMIfZYFYJ3/skq+V4JOBLmlhGlPExy6gqYwMz2uSJ1gR3 Kgl24aisbJ27zFi0E+w0DAM6qtK+mORJD0REsBOc+I74Jm51pwyVzGpvxB7NjD1JArlW Z1Nw3IJcwTpFcPc/OM/mDZYHlik6/X5+hBBgaF+RBWA6lCnTc9Su31yLYk3E+KZP8/w7 k1BrfTKfIXXZ46LHA5pZpwKRNzhgz58PNc7YyUV/9wiANk3u5qYBZVv8t0PgePg8ENXo Bcrg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=SCzz0vkCTXCJ+hl1sGhlu0aynSHOxUfyv4GiVUi2UT8=; b=KF+wOpBEt0zdXqLDX4RC+NWfEAiOTx9CCs9xbIJ0QxVrhRzF0YnmWF5RJlCti94a1R Iu537vUF8NtnQ/HM6c2JlSKG7CFFnLLSUr3M9HJprdHSOvNFqhNpX2r8NYHXdWos11aC HcXx5L55q+SozY3wWASLDxBWQfy7HVnTVx67qWrTA4RPg7DyJcbK0t5qq3nQat9VRmDE 59FA60T1PedBlPFuiNqucShB6GlAUYXaKMUOyZNy8fif7HcthybM0Zvg8G4VXsB0wE3G HvpmJ/ERKVU5McmTneYGpExTBEhIOUAN7m/C1jOqleCYEQEcIn6iVHbM1noyyRPkhOV1 mtzw== X-Gm-Message-State: AOAM5339+Xwv/GUJdlAc6UIWD059HkUb9iusVPfIyhUxV24PtSZmPxM7 rH7WLK+S9UuvVai8wr2emyCILH3nhkTMx4zyOsY= X-Google-Smtp-Source: ABdhPJwBMd/Hg8Inw/d+QCjcsX4aY1KphAmvmly7frqYXPa28oCDMQoPY4+7I2PpXYAYog1pvPg18bYfcaeLUFSg7M0= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:c0d7:a7ba:fb41:a35a]) (user=samitolvanen job=sendgmr) by 2002:a25:4ce:: with SMTP id 197mr429022ybe.462.1616087474808; Thu, 18 Mar 2021 10:11:14 -0700 (PDT) Date: Thu, 18 Mar 2021 10:10:54 -0700 Message-Id: <20210318171111.706303-1-samitolvanen@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v2 00/17] Add support for Clang CFI From: Sami Tolvanen To: Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Masahiro Yamada , Will Deacon , Jessica Yu , Arnd Bergmann , Tejun Heo , "Paul E. McKenney" , Christoph Hellwig , bpf@vger.kernel.org, linux-hardening@vger.kernel.org, linux-arch@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kbuild@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Sami Tolvanen Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org This series adds support for Clang's Control-Flow Integrity (CFI) checking. With CFI, the compiler injects a runtime check before each indirect function call to ensure the target is a valid function with the correct static type. This restricts possible call targets and makes it more difficult for an attacker to exploit bugs that allow the modification of stored function pointers. For more details, see: https://clang.llvm.org/docs/ControlFlowIntegrity.html The first patch contains build system changes and error handling, and implements support for cross-module indirect call checking. The remaining patches address issues caused by the compiler instrumentation. These include fixing known type mismatches, as well as issues with address space confusion and cross-module function address equality. These patches add support only for arm64, but I'll post patches also for x86_64 after we address the remaining issues there, including objtool support. You can also pull this series from https://github.com/samitolvanen/linux.git cfi-v2 --- Changes in v2: - Fixed .text merging in module.lds.S. - Added WARN_ON_FUNCTION_MISMATCH() and changed kernel/thread.c and kernel/workqueue.c to use the macro instead. Sami Tolvanen (17): add support for Clang CFI cfi: add __cficanonical mm: add generic __va_function and __pa_function macros module: ensure __cfi_check alignment workqueue: use WARN_ON_FUNCTION_MISMATCH kthread: use WARN_ON_FUNCTION_MISMATCH kallsyms: strip ThinLTO hashes from static functions bpf: disable CFI in dispatcher functions lib/list_sort: fix function type mismatches lkdtm: use __va_function psci: use __pa_function for cpu_resume arm64: implement __va_function arm64: use __pa_function arm64: add __nocfi to functions that jump to a physical address arm64: add __nocfi to __apply_alternatives KVM: arm64: Disable CFI for nVHE arm64: allow CONFIG_CFI_CLANG to be selected Makefile | 17 ++ arch/Kconfig | 45 +++ arch/arm64/Kconfig | 1 + arch/arm64/include/asm/memory.h | 15 + arch/arm64/include/asm/mmu_context.h | 4 +- arch/arm64/kernel/acpi_parking_protocol.c | 2 +- arch/arm64/kernel/alternative.c | 4 +- arch/arm64/kernel/cpu-reset.h | 10 +- arch/arm64/kernel/cpufeature.c | 4 +- arch/arm64/kernel/psci.c | 3 +- arch/arm64/kernel/smp_spin_table.c | 2 +- arch/arm64/kvm/hyp/nvhe/Makefile | 6 +- drivers/firmware/psci/psci.c | 4 +- drivers/misc/lkdtm/usercopy.c | 2 +- include/asm-generic/bug.h | 16 ++ include/asm-generic/vmlinux.lds.h | 20 +- include/linux/bpf.h | 4 +- include/linux/cfi.h | 41 +++ include/linux/compiler-clang.h | 3 + include/linux/compiler_types.h | 8 + include/linux/init.h | 6 +- include/linux/mm.h | 8 + include/linux/module.h | 13 +- include/linux/pci.h | 4 +- init/Kconfig | 2 +- kernel/Makefile | 4 + kernel/cfi.c | 329 ++++++++++++++++++++++ kernel/kallsyms.c | 54 +++- kernel/kthread.c | 3 +- kernel/module.c | 43 +++ kernel/workqueue.c | 2 +- lib/list_sort.c | 8 +- scripts/Makefile.modfinal | 2 +- scripts/module.lds.S | 18 +- 34 files changed, 663 insertions(+), 44 deletions(-) create mode 100644 include/linux/cfi.h create mode 100644 kernel/cfi.c base-commit: 6417f03132a6952cd17ddd8eaddbac92b61b17e0