On Wed, Aug 16, 2017 at 4:14 PM, Laura Abbott <labbott@xxxxxxxxxx> wrote: > From: Daniel Micay <danielmicay@xxxxxxxxx> > > > 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 <danielmicay@xxxxxxxxx> > [labbott: Line-wrapped command line] > Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx> Thanks! -Kees > --- > 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 > -- Kees Cook Pixel Security -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
