The patch titled Subject: init/main.c: extract early boot entropy from the passed cmdline has been added to the -mm tree. Its filename is extract-early-boot-entropy-from-the-passed-cmdline.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/extract-early-boot-entropy-from-the-passed-cmdline.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/extract-early-boot-entropy-from-the-passed-cmdline.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Daniel Micay <danielmicay@xxxxxxxxx> Subject: init/main.c: extract early boot entropy from the passed cmdline Feed the boot command-line as to the /dev/random entropy pool Existing Android bootloaders usually pass data which may not be known by an external attacker 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). [tytso@xxxxxxx: changelog tweak] [labbott@xxxxxxxxxx: line-wrapped command line] Link: http://lkml.kernel.org/r/20170816231458.2299-3-labbott@xxxxxxxxxx Signed-off-by: Daniel Micay <danielmicay@xxxxxxxxx> Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx> Acked-by: Kees Cook <keescook@xxxxxxxxxxxx> Cc: "Theodore Ts'o" <tytso@xxxxxxx> Cc: Laura Abbott <lauraa@xxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- init/main.c | 2 ++ 1 file changed, 2 insertions(+) diff -puN init/main.c~extract-early-boot-entropy-from-the-passed-cmdline init/main.c --- a/init/main.c~extract-early-boot-entropy-from-the-passed-cmdline +++ a/init/main.c @@ -530,8 +530,10 @@ asmlinkage __visible void __init start_k 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); _ Patches currently in -mm which might be from danielmicay@xxxxxxxxx are extract-early-boot-entropy-from-the-passed-cmdline.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html