[Miscellaneous Android Development] tecknight:
I know some of the Magisk support guys pretty well.

I reported and then helped them to resolve a weird intermittent permissions issue on /dev/null that was causing adbd to crater.

These guys work closely with topjohnwu. I will touch base with [MENTION=10392463]rlrevell[/MENTION] so I can understand exactly what the issue is, then pass it on to the guys I know. They work closely with topjohnwu, and it it makes sense to fix the issue, I think they will try to address it.

As a side note, I'm really impressed with rlrevell, he is very new to XDA, but has HUGE detailed knowlege and experience with linux internals. I think I will learn as much from him as he will learn from me.

PS: Looked up the RCA voyager details from my post, here is the build.prop.

Not sure if you can tell if it was exploitable:

Build.prop

# begin build properties

# autogenerated by buildinfo.sh

ro.build.id=MMB29M

ro.build.display.id=RCT6973W43-ANDROID6.0-V20-V1.16.50-E04

ro.build.version.incremental=eng.lxz.20161124.1454 04

ro.build.version.sdk=23

ro.build.version.preview_sdk=0

ro.build.version.codename=REL

ro.build.version.all_codenames=REL

ro.build.version.release=6.0.1

ro.build.version.security_patch=2016-06-01

ro.build.version.base_os=

ro.build.date=2016年 11月 24日 星期四 14:56:52 CST

ro.build.date.utc=1479970612

ro.build.type=user

ro.build.user=lxz

ro.build.host=ubuntu195

ro.build.tags=release-keys

ro.build.flavor=RCT6973W43-user

ro.product.model=RCT6973W43

ro.product.brand=RCA

ro.product.name=RCT6973W43

ro.product.device=sofia3gr

ro.product.board=rk30sdk

# ro.product.cpu.abi and ro.product.cpu.abi2 are obsolete,

# use ro.product.cpu.abilist instead.

ro.product.cpu.abi=x86

ro.product.cpu.abilist=x86,armeabi-v7a,armeabi

ro.product.cpu.abilist32=x86,armeabi-v7a,armeabi

ro.product.cpu.abilist64=

ro.product.manufacturer=Alco

ro.product.locale=en-US

ro.wifi.channels=

ro.board.platform=sofia3gr

# ro.build.product is obsolete; use ro.product.device

ro.build.product=sofia3gr

# Do not try to parse description, fingerprint, or thumbprint

ro.build.description=RCT6973W43-user 6.0.1 MMB29M eng.lxz.20161124.145404 release-keys

ro.build.fingerprint=RCA/RCT6973W43/RCT6973W43:6.0.1/MMB29M/hong08032023:user/release-keys

ro.build.characteristics=tablet

# end build properties

#

# from device/rockchip/sofia3gr/system.prop

#

#

# system.prop

#

#rild.libpath=/system/lib/libreference-ril.so

#rild.libargs=-d /dev/ttyUSB2

# Default ecclist

persist.tegra.nvmmlite = 1

ro.audio.monitorOrientation=true

#NFC

debug.nfc.fw_download=false

debug.nfc.se=false

#add Rockchip properties here

ro.rk.screenoff_time=60000

ro.rk.screenshot_enable=true

ro.rk.homepage_base=http://www.google.com/webhp?client={CID}&source=android-home

ro.rk.install_non_market_apps=false

sys.rkadb.root=0

ro.rk.MassStorage=false

ro.rk.systembar.voiceicon=true

ro.rk.systembar.tabletUI=false

ro.rk.LowBatteryBrightness=false

ro.default.size=100

ro.product.usbfactory=rockchip_usb

ro.factory.tool=0

#force camera API 1

#camera2.portability.force_api=1

#enable camera TAF and FaceDetect ui

persist.camera.debug_ui=1

#enable auto create media_profiles.xml

sys_graphic.cam_hal.at_profiles=true

sys_graphic.cam_normal.yuvout=true

#Sofia properties

ro.sofia_ota=true

#eboda lxz

ro.tether.denied=true

#ro.product.version=1.10.0

#ro.product.ota.host=tablet10.gyrodock.com:2300

ro.product.ota.host2=192.168.0.18:2300

persist.camera.capture_mode=1

persist.camera.preview_full=1

#

# ADDITIONAL_BUILD_PROPERTIES

#

persist.bt.defname=RCT6973W43

ro.product.version=1.16.50

ro.product.ota.host=tablet16.gyrodock.com:2300

ro.sf.lcd_density=160

ro.config.alarm_alert=Oxygen.ogg

ro.config.font_scale=1.08

persist.sys.usb.config=mtp

dalvik.vm.heapstartsize=8m

dalvik.vm.heapgrowthlimit=96m

dalvik.vm.heapsize=174m

dalvik.vm.heaptargetutilization=0.75

dalvik.vm.heapminfree=512k

dalvik.vm.heapmaxfree=2m

ro.config.enable.mtp_opt=true

keyguard.no_require_sim=true

persist.radio.multisim.config=false

persist.modem.disable=true

ro.config.set_language_by_sim=false

persist.service.low_level_freq=1040000

persist.service.boost_freq=1040000

persist.service.brightness=8

media.wfd.video-bitrate=3000000

wifi.interface=wlan0

ro.setupwizard.mode=OPTIONAL

ro.com.google.clientidbase=android-alco

ro.com.google.clientidbase.am=android-alco

ro.com.google.clientidbase.gmm=android-alco

ro.com.google.clientidbase.ms=android-alco

ro.com.google.clientidbase.yt=android-alco

ro.com.google.gmsversion=6.0_r5

ro.frp.pst=/dev/block/platform/soc0/e0000000.noc/by-name/ImcPartID034

ro.rk.gms_cer=true

persist.audio.log=0

drm.service.enabled=true

camera.disable_zsl_mode=1

ro.hwui.texture_cache_size=36.0f

ro.hwui.text_large_cache_width=2048

ro.hwui.text_large_cache_height=1024

ro.sf.hwrotation=180

ro.opengles.version=131072

persist.sys.media.use-awesome=true

debug.hwui.render_dirty_regions=false

sys.hwc.compose_policy=6

sys.hwc.enable=1

persist.sys.ui.hw=false

ro.adb.secure=1

rild.libpath=/system/lib/libril-rk29-dataonly.so

rild.libargs=-d

/dev/ttyACM0

ro.tether.denied=false

persist.sys.strictmode.visual=0

persist.sys.strictmode.disable=1

persist.sys.alarm.fixed=300000

ro.sms.address_enable=false

ro.config.sim_switch=true

ro.config.accessibility=1

ro.config.favourite_channel=1

ro.config.offline_read=1

ro.config.power_off_alarm=1

ro.config.sheduled_power=1

ro.config.speed_dial=1

ro.config.builtin_cdrom=1

ro.config.charge_only=1

ro.config.black_list=0

ro.dalvik.vm.isa.arm=x86

ro.enable.native.bridge.exec=1

ro.sf.lcdc_composer=0

ro.config.ringtone=Ring_Synth_04.ogg

ro.config.notification_sound=pixiedust.ogg

ro.carrier=unknown

persist.sys.dalvik.vm.lib.2=libart

dalvik.vm.isa.x86.variant=silvermont

dalvik.vm.isa.x86.features=default

net.bt.name=Android

dalvik.vm.stack-trace-file=/data/anr/traces.txt

ro.expect.recovery_id=0xf5bbb0762b0719f9bb6c50f6f2 0bab38e54a76de000000000000000000000000

Partitions:

major minor #blocks name

179 0 15106048 mmcblk0

179 1 8192 mmcblk0p1

179 2 1024 mmcblk0p2

179 3 1024 mmcblk0p3

179 4 1024 mmcblk0p4

179 5 5120 mmcblk0p5

179 6 1024 mmcblk0p6

179 7 4096 mmcblk0p7

179 8 12288 mmcblk0p8

179 9 16384 mmcblk0p9 -> boot

179 10 16384 mmcblk0p10 -> recovery

179 11 23552 mmcblk0p11

179 12 32768 mmcblk0p12

179 13 2048 mmcblk0p13

179 14 8192 mmcblk0p14

179 15 435200 mmcblk0p15

179 16 3407872 mmcblk0p16

179 17 11111424 mmcblk0p17

179 18 2048 mmcblk0p18

179 96 4096 mmcblk0rpmb

179 64 4096 mmcblk0boot1

179 32 4096 mmcblk0boot0

179 128 31166976 mmcblk1

179 129 31150592 mmcblk1p1

By name:

lrwxrwxrwx 1 root root 20 Oct 21 04:37 ImcPartID001 -> /dev/block/mmcblk0p7

lrwxrwxrwx 1 root root 20 Oct 21 04:37 ImcPartID010 -> /dev/block/mmcblk0p4

lrwxrwxrwx 1 root root 21 Oct 21 04:37 ImcPartID013 -> /dev/block/mmcblk0p11

lrwxrwxrwx 1 root root 20 Oct 21 04:37 ImcPartID022 -> /dev/block/mmcblk0p1

lrwxrwxrwx 1 root root 20 Oct 21 04:37 ImcPartID023 -> /dev/block/mmcblk0p2

lrwxrwxrwx 1 root root 20 Oct 21 04:37 ImcPartID024 -> /dev/block/mmcblk0p3

lrwxrwxrwx 1 root root 21 Oct 21 04:37 ImcPartID033 -> /dev/block/mmcblk0p14

lrwxrwxrwx 1 root root 21 Oct 21 04:37 ImcPartID034 -> /dev/block/mmcblk0p13

lrwxrwxrwx 1 root root 21 Oct 21 04:37 ImcPartID068 -> /dev/block/mmcblk0p16

lrwxrwxrwx 1 root root 21 Oct 21 04:37 ImcPartID069 -> /dev/block/mmcblk0p17

lrwxrwxrwx 1 root root 21 Oct 21 04:37 ImcPartID070 -> /dev/block/mmcblk0p15

lrwxrwxrwx 1 root root 20 Oct 21 04:37 ImcPartID071 -> /dev/block/mmcblk0p9

lrwxrwxrwx 1 root root 21 Oct 21 04:37 ImcPartID074 -> /dev/block/mmcblk0p18

lrwxrwxrwx 1 root root 20 Oct 21 04:37 ImcPartID076 -> /dev/block/mmcblk0p5

lrwxrwxrwx 1 root root 20 Oct 21 04:37 ImcPartID115 -> /dev/block/mmcblk0p6

lrwxrwxrwx 1 root root 20 Oct 21 04:37 ImcPartID118 -> /dev/block/mmcblk0p8

lrwxrwxrwx 1 root root 21 Oct 21 04:37 ImcPartID121 -> /dev/block/mmcblk0p10

lrwxrwxrwx 1 root root 21 Oct 21 04:37 ImcPartID122 -> /dev/block/mmcblk0p12