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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS 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 5C31FC433B4 for ; Wed, 31 Mar 2021 21:46:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 029EB61078 for ; Wed, 31 Mar 2021 21:46:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231339AbhCaVqV (ORCPT ); Wed, 31 Mar 2021 17:46:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231676AbhCaVqL (ORCPT ); Wed, 31 Mar 2021 17:46:11 -0400 Received: from mail-pj1-x1031.google.com (mail-pj1-x1031.google.com [IPv6:2607:f8b0:4864:20::1031]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D70F5C06175F for ; Wed, 31 Mar 2021 14:46:10 -0700 (PDT) Received: by mail-pj1-x1031.google.com with SMTP id x21-20020a17090a5315b029012c4a622e4aso1988138pjh.2 for ; Wed, 31 Mar 2021 14:46:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=esAh+eFc7x1e4muSLkstj3Ic+kmZW4D/uno+GAwyPqg=; b=NzeLyJir6d1KwpiZ3RmekcvSne/weQo4YA0Uu7Q89IkbPP0+5tkV6E7R5TuBWawoMg idGZp8zqhG+5HVjnv+msYLiZQ9S7h9tCa6GvjbE5b83fycdA9pvVk1tDXnlDajKP2SLi 74sdgQx/uoB7+AwHV0v7j226PbBND6y7yHvDI= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=esAh+eFc7x1e4muSLkstj3Ic+kmZW4D/uno+GAwyPqg=; b=XMhhZC/n6TGmcXIcWIqznQq93WcOHDaK+wrOkh585ULTD1EsK8C57O9cMy6pn2NQMN AN0IUU9CAoJFb3XcYDzAjStTBRfx1c3rG7SXldsd1qr2TemcBeZ4yaUDByPtVKJm0eqi w+Mkm/qJLv4jhK14QiPFt/W5memxHrkPkw8YEmznHQpC28dT4BSOAoqC7tK/NB5Yct6c 3825oZpOJ6JWD4LwOKF9tWEgtXrjGgLyqboiPq1qP4DVMh4KFahwcPEcun7KP8QLNRCn Qiq0KHaTZKgWKlWfakBR2H/vay+KM++5cMqirIHjwi7EQwnva0L96majtwFxz/9Pl13n Ejqg== X-Gm-Message-State: AOAM532rnOQXc/DByhwsI/yeTP22pj3NnLPpmVRpf8D7UAFM7luYwExX La5vctvsGzJOJyk+0+6kJKqdtg== X-Google-Smtp-Source: ABdhPJyc6xYrPp/zlyE7RCl/S1V/S62i7LtVAPCykyeZ+e4UWpT04Q1Ln+T2FDOVuAGVX7rqBciSng== X-Received: by 2002:a17:90a:be0e:: with SMTP id a14mr5187306pjs.131.1617227170242; Wed, 31 Mar 2021 14:46:10 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id iq6sm3106930pjb.31.2021.03.31.14.46.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 31 Mar 2021 14:46:09 -0700 (PDT) Date: Wed, 31 Mar 2021 14:46:08 -0700 From: Kees Cook To: Sami Tolvanen 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, Catalin Marinas , Mark Rutland Subject: Re: [PATCH v4 00/17] Add support for Clang CFI Message-ID: <202103311442.FDB6E8223@keescook> References: <20210331212722.2746212-1-samitolvanen@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210331212722.2746212-1-samitolvanen@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Mar 31, 2021 at 02:27:04PM -0700, Sami Tolvanen wrote: > 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 Thanks for the updates! I think this is ready to land in -next. Will, Mark, Catalin: would you prefer this go via arm64 or via my LTO tree? (Or does anyone see other stuff they'd like fixed first?) -Kees > --- > 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 > -- > 2.31.0.291.g576ba9dcdaf-goog > -- Kees Cook