From patchwork Wed Mar 31 21:27:04 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12176387 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, USER_AGENT_GIT,USER_IN_DEF_DKIM_WL autolearn=unavailable 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 758B5C43611 for ; Wed, 31 Mar 2021 21:28:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56B3361055 for ; Wed, 31 Mar 2021 21:28:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232467AbhCaV1e (ORCPT ); Wed, 31 Mar 2021 17:27:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51696 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230291AbhCaV1Z (ORCPT ); Wed, 31 Mar 2021 17:27:25 -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 D1496C06175F for ; Wed, 31 Mar 2021 14:27:24 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id y13so3611163ybk.20 for ; Wed, 31 Mar 2021 14:27:24 -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=yTP+LjBFDmYzEkZN/ojSVPqO+bAHNBu2aAmdwQC8Sq0=; b=IImtgBJ7yAhdvPcjObAuget2Jumf3PaCW/76HUIX7raQTGWs3yNE9WoPlH1zK6Q1u4 +7jYJb6uW1OS281+twBaFF73GLAuKSTPkEbScEk2CWC9E+ti1FwiAPHe8Wbe1//KUbjL p+kRmfOunTBE7ZEh3NxO0tHeV4EUi6uiuuwGTA81RWeaZZ2Xjnt/4baMCb8b5+Fu7aso 9/gyF3XK113vGJ96dbjy4rWUJO2LXn66iORt+eQxiaRmhqAP1anwF+wgvtGqNUrXORGu i4cblL+YQtoV/evE8Hf9ig9e6yT+Kxf/odgiUwus7g8QgOHtY6Ewb2hW78AIWe2OImPx Wjgw== 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=yTP+LjBFDmYzEkZN/ojSVPqO+bAHNBu2aAmdwQC8Sq0=; b=i37pa5La8ffXq5Z+MuyKh6htJVj1elAuLW1nD616KD3eI534KeS3A5s+OrqYfHbhpW y4dtm/+/wfIYyvwPHsw9zKiL0v2hIJ4lPwQTOEUjVUpkpd7yCVjo9U6zZaCB2U1rvSGo Y/TKnHxCAruwBDTuu6Mg5mxhdmi/jAhSVFMmJOyfokaolqUNQDG+rWA7JcH14EK84ZDg 2PdDjeNaKnP6F5gE72auKXCgkD9ijEcUZ4xNQfzlU07pjh5mOPoScZEIXHr328fG6FAt skjNy/VX/6t2pYtJQswNgkrdPR8skk5Agl5VzdxXNzaLGFcttvDwazVEQ6dUU7Tfch+/ VWWg== X-Gm-Message-State: AOAM533w1CIc1Aeta2rtuDBgijtHEknEtlDrdzYiQ5g8QqhDJzl1SR7j HGMqlQcV0GbL5FgoFbXfzViTEsZgK9vEHS51gz4= X-Google-Smtp-Source: ABdhPJxEEWvfo80m5ShoYqPvblwqvUS4wssFRgdGlX1k6EZR1yPZFQwGxomYdq2wD1SGfu2YEhzp2R2AwbgiIYN6I9g= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:7933:7015:a5d5:3835]) (user=samitolvanen job=sendgmr) by 2002:a25:2386:: with SMTP id j128mr7405063ybj.284.1617226044066; Wed, 31 Mar 2021 14:27:24 -0700 (PDT) Date: Wed, 31 Mar 2021 14:27:04 -0700 Message-Id: <20210331212722.2746212-1-samitolvanen@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v4 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 , Peter Zijlstra , Sedat Dilek , 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, clang-built-linux@googlegroups.com, 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-v4 --- Changes in v4: - Per Mark's suggestion, dropped __pa_function() and renamed __va_function() to function_nocfi(). - Added a comment to function_nocfi() to explain what it does. - Updated the psci patch to use an intermediate variable for the physical address for clarity. Changes in v3: - Added a patch to change list_sort() callers treewide to use const pointers instead of simply removing the internal casts. - Changed cleanup_symbol_name() to return bool. - Changed module.lds.S to drop the .eh_frame section only with CONFIG_CFI_CLANG. - Switched to synchronize_rcu() in update_shadow(). 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 function_nocfi macro 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 treewide: Change list_sort to use const pointers lkdtm: use function_nocfi psci: use function_nocfi for cpu_resume arm64: implement function_nocfi arm64: use function_nocfi with __pa_symbol 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 | 3 +- 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 | 3 +- arch/arm64/kvm/hyp/nvhe/Makefile | 6 +- arch/arm64/kvm/vgic/vgic-its.c | 8 +- arch/arm64/kvm/vgic/vgic.c | 3 +- block/blk-mq-sched.c | 3 +- block/blk-mq.c | 3 +- drivers/acpi/nfit/core.c | 3 +- drivers/acpi/numa/hmat.c | 3 +- drivers/clk/keystone/sci-clk.c | 4 +- drivers/firmware/psci/psci.c | 7 +- drivers/gpu/drm/drm_modes.c | 3 +- drivers/gpu/drm/i915/gt/intel_engine_user.c | 3 +- drivers/gpu/drm/i915/gvt/debugfs.c | 2 +- drivers/gpu/drm/i915/selftests/i915_gem_gtt.c | 3 +- drivers/gpu/drm/radeon/radeon_cs.c | 4 +- .../hw/usnic/usnic_uiom_interval_tree.c | 3 +- drivers/interconnect/qcom/bcm-voter.c | 2 +- drivers/md/raid5.c | 3 +- drivers/misc/lkdtm/usercopy.c | 2 +- drivers/misc/sram.c | 4 +- drivers/nvme/host/core.c | 3 +- .../controller/cadence/pcie-cadence-host.c | 3 +- drivers/spi/spi-loopback-test.c | 3 +- fs/btrfs/raid56.c | 3 +- fs/btrfs/tree-log.c | 3 +- fs/btrfs/volumes.c | 3 +- fs/ext4/fsmap.c | 4 +- fs/gfs2/glock.c | 3 +- fs/gfs2/log.c | 2 +- fs/gfs2/lops.c | 3 +- fs/iomap/buffered-io.c | 3 +- fs/ubifs/gc.c | 7 +- fs/ubifs/replay.c | 4 +- fs/xfs/scrub/bitmap.c | 4 +- fs/xfs/xfs_bmap_item.c | 4 +- fs/xfs/xfs_buf.c | 6 +- fs/xfs/xfs_extent_busy.c | 4 +- fs/xfs/xfs_extent_busy.h | 3 +- fs/xfs/xfs_extfree_item.c | 4 +- fs/xfs/xfs_refcount_item.c | 4 +- fs/xfs/xfs_rmap_item.c | 4 +- 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/list_sort.h | 7 +- include/linux/mm.h | 10 + include/linux/module.h | 13 +- include/linux/pci.h | 4 +- init/Kconfig | 2 +- kernel/Makefile | 4 + kernel/cfi.c | 329 ++++++++++++++++++ kernel/kallsyms.c | 55 ++- kernel/kthread.c | 3 +- kernel/module.c | 43 +++ kernel/workqueue.c | 2 +- lib/list_sort.c | 17 +- lib/test_list_sort.c | 3 +- net/tipc/name_table.c | 4 +- scripts/Makefile.modfinal | 2 +- scripts/module.lds.S | 20 +- 74 files changed, 759 insertions(+), 112 deletions(-) create mode 100644 include/linux/cfi.h create mode 100644 kernel/cfi.c base-commit: d19cc4bfbff1ae72c3505a00fb8ce0d3fa519e6c