From patchwork Fri Jul 31 23:07:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kees Cook X-Patchwork-Id: 11695559 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B76CB138A for ; Fri, 31 Jul 2020 23:09:41 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8F3F620836 for ; Fri, 31 Jul 2020 23:09:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="goPvHxzn"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="MLXUvi1E" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8F3F620836 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=chromium.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=mY+JKIDni5qZzfiJVtZGdy4DB6OkCwykYhAAg7Pic20=; b=goPvHxznRDIDFU2sAyK5YFKWo OPf9Gwo7SSJBJ+7k6fQnACVJwZMHdx2dVn/D9fYehDgZ6hfCMctdlymnXg5qb1SpkM2/J6FrUeBoL JGpXe6/JMe75VsI7FGJXrDPmqJE35snG5qzd39W/y+kFR/dmA2/PlyBEIK4xU5rVUhzWfjlxpuXZo XLoRs9Ieeg8ogy9+KKpv01v22xfYhO4owFYAJtPfwi8asb9cgaGOs8pGKK6UajA9EAPJ/k9SnmTNE 8DwlsfBJI5d4Qb/wE9X4Fkbhoe2z2QLcVknZnkUpHMEvKunXUuMZbsqJOmL1/on+wukR3i5kM7tu/ Wl491yWrw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1k1e9V-0008Pu-Rs; Fri, 31 Jul 2020 23:09:25 +0000 Received: from mail-pf1-x42a.google.com ([2607:f8b0:4864:20::42a]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1k1e8n-000869-1t for linux-arm-kernel@lists.infradead.org; Fri, 31 Jul 2020 23:08:50 +0000 Received: by mail-pf1-x42a.google.com with SMTP id l2so8848354pff.0 for ; Fri, 31 Jul 2020 16:08:40 -0700 (PDT) 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 :mime-version:content-transfer-encoding; bh=wOq+Y00LQi/3deraAM6kBuaQbRKnLYOHk6N+NuQVWdA=; b=MLXUvi1EuKG0FE+rIsbID9rRvyHhHP/bC/1H8WYBKVP5ZSFhWYwP+lP5XZpTQ06Bf0 wv4BfOauML6dkzya4CuKy7gALZ+W+9xqlhpjxWQqkL5+umqTPynzx2CVlkxuPT6WpFPO j+sa9r0Kjrijgwt3APFSfc7Wq1KUkGc2Bq+kU= 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:mime-version:content-transfer-encoding; bh=wOq+Y00LQi/3deraAM6kBuaQbRKnLYOHk6N+NuQVWdA=; b=jUoiQzYCtb8oF9JIk0mCbaKlnwmG5SFsVQGiwQTofxEtS/WsEpUuc2MzujUKdMGHq3 hk7yXx/norhkc1icmHcIC+TTKvtF71FTwxIuYm1KLdg57x/qJYaH+gEkiNsemkoEZBbt xzWT4Hrs/U7JAdEzhn9rxLPO6HMRftU0il5xyjfSu0/GgnIphyIe06TTTWbxTVzF8f6A auae9neJxAUbKbM4jYPYITEy+uCPgDV6UKS+wzJEuS1Vzg5oJQICOYcGJ6Jq4Qbiq64M kGzxhb6tk1jnz1UdetZ+zCsKKSsrI92E7gdmDDIrf0NUMQ5v2sAVYl8KZtwrhRtEx/t1 bVVA== X-Gm-Message-State: AOAM5321a3nk6rJP1ZJ6sfgN7GIU4ThXyCbTi4oa+W1+5YECqI8gpe6u RdGwWNQxshbyAzzu4hXpqJjySA== X-Google-Smtp-Source: ABdhPJxilVrjiuHEI9OJNGFNpHOWI1BRRuP7pZ9ogDRckvVa3npz7ZCMJpdwxdsXaIoH3Zh78zy0uA== X-Received: by 2002:a65:620f:: with SMTP id d15mr5623976pgv.270.1596236918800; Fri, 31 Jul 2020 16:08:38 -0700 (PDT) Received: from www.outflux.net (smtp.outflux.net. [198.145.64.163]) by smtp.gmail.com with ESMTPSA id m190sm9732049pfm.89.2020.07.31.16.08.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 31 Jul 2020 16:08:35 -0700 (PDT) From: Kees Cook To: Thomas Gleixner , Will Deacon Subject: [PATCH v5 07/36] x86/boot: Check that there are no run-time relocations Date: Fri, 31 Jul 2020 16:07:51 -0700 Message-Id: <20200731230820.1742553-8-keescook@chromium.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200731230820.1742553-1-keescook@chromium.org> References: <20200731230820.1742553-1-keescook@chromium.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200731_190841_434869_9E4700BE X-CRM114-Status: GOOD ( 18.29 ) X-Spam-Score: -0.2 (/) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-0.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 RCVD_IN_DNSWL_NONE RBL: Sender listed at https://www.dnswl.org/, no trust [2607:f8b0:4864:20:0:0:0:42a listed in] [list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record 0.0 SPF_HELO_NONE SPF: HELO does not publish an SPF Record -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.0 DKIMWL_WL_HIGH DKIMwl.org - Whitelisted High sender X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , linux-efi@vger.kernel.org, Catalin Marinas , Arvind Sankar , Ard Biesheuvel , linux-arch@vger.kernel.org, Fangrui Song , Masahiro Yamada , x86@kernel.org, Russell King , clang-built-linux@googlegroups.com, Ingo Molnar , Borislav Petkov , Kees Cook , Arnd Bergmann , Sedat Dilek , Nathan Chancellor , Peter Collingbourne , linux-arm-kernel@lists.infradead.org, Nick Desaulniers , linux-kernel@vger.kernel.org, James Morse Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org From: Arvind Sankar Add a linker script check that there are no run-time relocations, and remove the old one that tries to check via looking for specially-named sections in the object files. Drop the tests for -fPIE compiler option and -pie linker option, as they are available in all supported gcc and binutils versions (as well as clang and lld). Tested-by: Nick Desaulniers Reviewed-by: Kees Cook Reviewed-by: Ard Biesheuvel Reviewed-by: Fangrui Song Reviewed-by: Sedat Dilek Tested-by: Sedat Dilek Signed-off-by: Arvind Sankar Signed-off-by: Kees Cook --- arch/x86/boot/compressed/Makefile | 28 +++----------------------- arch/x86/boot/compressed/vmlinux.lds.S | 8 ++++++++ 2 files changed, 11 insertions(+), 25 deletions(-) diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index 7db0102a573d..96d53e300ab6 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -29,7 +29,7 @@ targets := vmlinux vmlinux.bin vmlinux.bin.gz vmlinux.bin.bz2 vmlinux.bin.lzma \ vmlinux.bin.xz vmlinux.bin.lzo vmlinux.bin.lz4 KBUILD_CFLAGS := -m$(BITS) -O2 -KBUILD_CFLAGS += -fno-strict-aliasing $(call cc-option, -fPIE, -fPIC) +KBUILD_CFLAGS += -fno-strict-aliasing -fPIE KBUILD_CFLAGS += -DDISABLE_BRANCH_PROFILING cflags-$(CONFIG_X86_32) := -march=i386 cflags-$(CONFIG_X86_64) := -mcmodel=small @@ -51,7 +51,7 @@ UBSAN_SANITIZE :=n KBUILD_LDFLAGS := -m elf_$(UTS_MACHINE) # Compressed kernel should be built as PIE since it may be loaded at any # address by the bootloader. -LDFLAGS_vmlinux := $(call ld-option, -pie) $(call ld-option, --no-dynamic-linker) +LDFLAGS_vmlinux := -pie $(call ld-option, --no-dynamic-linker) LDFLAGS_vmlinux += -T hostprogs := mkpiggy @@ -86,30 +86,8 @@ vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a -# The compressed kernel is built with -fPIC/-fPIE so that a boot loader -# can place it anywhere in memory and it will still run. However, since -# it is executed as-is without any ELF relocation processing performed -# (and has already had all relocation sections stripped from the binary), -# none of the code can use data relocations (e.g. static assignments of -# pointer values), since they will be meaningless at runtime. This check -# will refuse to link the vmlinux if any of these relocations are found. -quiet_cmd_check_data_rel = DATAREL $@ -define cmd_check_data_rel - for obj in $(filter %.o,$^); do \ - $(READELF) -S $$obj | grep -qF .rel.local && { \ - echo "error: $$obj has data relocations!" >&2; \ - exit 1; \ - } || true; \ - done -endef - -# We need to run two commands under "if_changed", so merge them into a -# single invocation. -quiet_cmd_check-and-link-vmlinux = LD $@ - cmd_check-and-link-vmlinux = $(cmd_check_data_rel); $(cmd_ld) - $(obj)/vmlinux: $(vmlinux-objs-y) $(efi-obj-y) FORCE - $(call if_changed,check-and-link-vmlinux) + $(call if_changed,ld) OBJCOPYFLAGS_vmlinux.bin := -R .comment -S $(obj)/vmlinux.bin: vmlinux FORCE diff --git a/arch/x86/boot/compressed/vmlinux.lds.S b/arch/x86/boot/compressed/vmlinux.lds.S index a4a4a59a2628..29df99b6cc64 100644 --- a/arch/x86/boot/compressed/vmlinux.lds.S +++ b/arch/x86/boot/compressed/vmlinux.lds.S @@ -42,6 +42,12 @@ SECTIONS *(.rodata.*) _erodata = . ; } + .rel.dyn : { + *(.rel.*) + } + .rela.dyn : { + *(.rela.*) + } .got : { *(.got) } @@ -85,3 +91,5 @@ ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0x18, "Unexpected GOT/PLT en #else ASSERT(SIZEOF(.got.plt) == 0 || SIZEOF(.got.plt) == 0xc, "Unexpected GOT/PLT entries detected!") #endif + +ASSERT(SIZEOF(.rel.dyn) == 0 && SIZEOF(.rela.dyn) == 0, "Unexpected run-time relocations detected!")