From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752567AbdHPXPL (ORCPT ); Wed, 16 Aug 2017 19:15:11 -0400 Received: from mail-qk0-f169.google.com ([209.85.220.169]:36397 "EHLO mail-qk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752524AbdHPXPI (ORCPT ); Wed, 16 Aug 2017 19:15:08 -0400 From: Laura Abbott To: Kees Cook Cc: Daniel Micay , kernel-hardening@lists.openwall.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Andrew Morton , Laura Abbott Subject: [PATCHv3 2/2] extract early boot entropy from the passed cmdline Date: Wed, 16 Aug 2017 16:14:58 -0700 Message-Id: <20170816231458.2299-3-labbott@redhat.com> X-Mailer: git-send-email 2.13.0 In-Reply-To: <20170816231458.2299-1-labbott@redhat.com> References: <20170816231458.2299-1-labbott@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Daniel Micay Existing Android bootloaders usually pass data useful as early entropy on the kernel command-line. It may also be the case on other embedded systems. Sample command-line from a Google Pixel running CopperheadOS: console=ttyHSL0,115200,n8 androidboot.console=ttyHSL0 androidboot.hardware=sailfish user_debug=31 ehci-hcd.park=3 lpm_levels.sleep_disabled=1 cma=32M@0-0xffffffff buildvariant=user veritykeyid=id:dfcb9db0089e5b3b4090a592415c28e1cb4545ab androidboot.bootdevice=624000.ufshc androidboot.verifiedbootstate=yellow androidboot.veritymode=enforcing androidboot.keymaster=1 androidboot.serialno=FA6CE0305299 androidboot.baseband=msm mdss_mdp.panel=1:dsi:0:qcom,mdss_dsi_samsung_ea8064tg_1080p_cmd:1:none:cfg:single_dsi androidboot.slot_suffix=_b fpsimd.fpsimd_settings=0 app_setting.use_app_setting=0 kernelflag=0x00000000 debugflag=0x00000000 androidboot.hardware.revision=PVT radioflag=0x00000000 radioflagex1=0x00000000 radioflagex2=0x00000000 cpumask=0x00000000 androidboot.hardware.ddr=4096MB,Hynix,LPDDR4 androidboot.ddrinfo=00000006 androidboot.ddrsize=4GB androidboot.hardware.color=GRA00 androidboot.hardware.ufs=32GB,Samsung androidboot.msm.hw_ver_id=268824801 androidboot.qf.st=2 androidboot.cid=11111111 androidboot.mid=G-2PW4100 androidboot.bootloader=8996-012001-1704121145 androidboot.oem_unlock_support=1 androidboot.fp_src=1 androidboot.htc.hrdump=detected androidboot.ramdump.opt=mem@2g:2g,mem@4g:2g androidboot.bootreason=reboot androidboot.ramdump_enable=0 ro root=/dev/dm-0 dm="system none ro,0 1 android-verity /dev/sda34" rootwait skip_initramfs init=/init androidboot.wificountrycode=US androidboot.boottime=1BLL:85,1BLE:669,2BLL:0,2BLE:1777,SW:6,KL:8136 Among other things, it contains a value unique to the device (androidboot.serialno=FA6CE0305299), unique to the OS builds for the device variant (veritykeyid=id:dfcb9db0089e5b3b4090a592415c28e1cb4545ab) and timings from the bootloader stages in milliseconds (androidboot.boottime=1BLL:85,1BLE:669,2BLL:0,2BLE:1777,SW:6,KL:8136). Signed-off-by: Daniel Micay [labbott: Line-wrapped command line] Signed-off-by: Laura Abbott --- v3: add_device_randomness comes before canary initialization, clarified comment. --- init/main.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/init/main.c b/init/main.c index 21d599eaad06..ba2b3a8a2382 100644 --- a/init/main.c +++ b/init/main.c @@ -530,8 +530,10 @@ asmlinkage __visible void __init start_kernel(void) setup_arch(&command_line); /* * Set up the the initial canary and entropy after arch + * and after adding latent and command line entropy. */ add_latent_entropy(); + add_device_randomness(command_line, strlen(command_line)); boot_init_stack_canary(); mm_init_cpumask(&init_mm); setup_command_line(command_line); -- 2.13.0