From patchwork Tue Mar 23 20:39:29 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 12159251 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=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 D625DC433C1 for ; Tue, 23 Mar 2021 20:40:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A29EB619BA for ; Tue, 23 Mar 2021 20:40:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233425AbhCWUj7 (ORCPT ); Tue, 23 Mar 2021 16:39:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233446AbhCWUjt (ORCPT ); Tue, 23 Mar 2021 16:39:49 -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 7FD9AC0613D9 for ; Tue, 23 Mar 2021 13:39:49 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id i2so636006ybl.21 for ; Tue, 23 Mar 2021 13:39:49 -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=WCFGTI2MzQSIA8TA7+0NNDS7r3FMw1zz4PI7vRl6tz8=; b=L8ISBtfVqQC1eYGzosYom8Yam4Fe6VlMONouaFNd/YHRoKYHe1m+fYaD4rhMjD4TA8 AM3Tsm5hGrsyh9yYIl54rZGH/XXhPCGDx12B/2/Lw8VB9yEGLhABM04Jrthk5p+igMKE FQtAcHPrTYnmp0ve2ntMLsef6hA5RwvpREqpDE8sAP/ULFRUvmDiqVv6ZPeZVsX4uG7a 6rHMM+sECywBkU5Figcf/kSMze4goqu7iEqiFWU+5VTPdyX1tZsGJ6J4ipJApbyR9Sh6 mzaDp969NaXlEKbb56wgl2pNCrRZR7zNRQa5H/gSqP+1Hd/sGjho3HuTvsQdGrIZ+Wkn jcZg== 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=WCFGTI2MzQSIA8TA7+0NNDS7r3FMw1zz4PI7vRl6tz8=; b=bdjodClX0FzlkFaFlw+F62OsRxtjx8CKKsHDYs5qD+I1p7kc2YvQSu8BTFOlgfGurq jSeu+jSiYnzi4xW0XOeY/0i6WI8kp8wGX/N4amR7KmBJZLppf9lgwzgosuYgTSO8PcrG /JF+OUfxfRBvYrVQZw7tjjlvu04xom2ptkvGKHthxsD1l5Ix2Yb/A0Amu1YHaRMvQbTD omiHv/xsEJmYK2H3z3xcHKkd3GRD7QmkIpHeZhNzKMTDQYmH/KSmqVR9Or0hgOpDZpbQ 92ojzqYDWdykGYrFa5I/vZfWSxG/yom0pQ69zQASRF4+RRh1Nlb/ujM5Ur0YjuKGs334 QiIw== X-Gm-Message-State: AOAM530XvRP8XCSQkOrbLS5yBoYNM/hzIT33mBRBJtzmCgR2GarlzXIx Hxby8hhvkw/YMQ+d1DOtauf3ksQaRj/ERoXuygM= X-Google-Smtp-Source: ABdhPJypNxMQPGcrvIUiNtiewpRG4S5rvp+CN7WrRUDRG8x0unI1VBhT3RaBBZmMcMEJjVZj4B32NowbtE9isxFNPjw= X-Received: from samitolvanen1.mtv.corp.google.com ([2620:15c:201:2:e9a3:260d:763b:67dc]) (user=samitolvanen job=sendgmr) by 2002:a25:868c:: with SMTP id z12mr43352ybk.389.1616531988566; Tue, 23 Mar 2021 13:39:48 -0700 (PDT) Date: Tue, 23 Mar 2021 13:39:29 -0700 Message-Id: <20210323203946.2159693-1-samitolvanen@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.31.0.291.g576ba9dcdaf-goog Subject: [PATCH v3 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 , 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: bpf@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-v3 --- 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 __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 treewide: Change list_sort to use const pointers 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 +- 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 | 4 +- 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 | 8 + 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, 752 insertions(+), 112 deletions(-) create mode 100644 include/linux/cfi.h create mode 100644 kernel/cfi.c base-commit: 7acac4b3196caee5e21fb5ea53f8bc124e6a16fc