Upgrade of Oracle Restart/SIHA from 11.2 to 12.2 fails with CRS-2415

We are in the process of upgrading our Oracle Clusters and SIHA/Restart systems to Oracle 12.2.0.1

The upgrade of the Grid-Infra home on a Oracle SIHA/Restart system from 11.2.0.4 to 12.2.0.1 fails when
running rootupgrade.sh with error message:

CRS-2415: Resource ‘ora.asm’ cannot be registered because its owner ‘root’ is not the same as the Oracle Restart user ‘oracle’

We start the upgrade to 12.2.0.1 (with Jan2018 RU patch) as:
$ ./gridSetup.sh -applyPSU /app/software/27100009

The installation and relink of the software looks correct.
However, when running the rootupgrade.sh as root user, as part of the post-installation,
the script ends with :

2018-03-28 11:20:27: Executing cmd: /app/gi/12201_grid/bin/crsctl query has softwareversion
2018-03-28 11:20:27: Command output:
> Oracle High Availability Services version on the local node is [12.2.0.1.0]
>End Command output
2018-03-28 11:20:27: Version String passed is: [Oracle High Availability Services version on the local node is [12.2.0.1.0]]
2018-03-28 11:20:27: Version Info returned is : [12.2.0.1.0]
2018-03-28 11:20:27: Got CRS softwareversion for su025p074: 12.2.0.1.0
2018-03-28 11:20:27: The software version on su025p074 is 12.2.0.1.0
2018-03-28 11:20:27: leftVersion=11.2.0.4.0; rightVersion=12.2.0.0.0
2018-03-28 11:20:27: [11.2.0.4.0] is lower than [12.2.0.0.0]
2018-03-28 11:20:27: Disable the SRVM_NATIVE_TRACE for srvctl command on pre-12.2.
2018-03-28 11:20:27: Invoking “/app/gi/12201_grid/bin/srvctl upgrade model -s 11.2.0.4.0 -d 12.2.0.1.0 -p first”
2018-03-28 11:20:27: trace file=/app/oracle/crsdata/su025p074/crsconfig/srvmcfg1.log
2018-03-28 11:20:27: Executing cmd: /app/gi/12201_grid/bin/srvctl upgrade model -s 11.2.0.4.0 -d 12.2.0.1.0 -p first
2018-03-28 11:21:02: Command output:
> PRCA-1003 : Failed to create ASM asm resource ora.asm
> PRCR-1071 : Failed to register or update resource ora.asm
> CRS-2415: Resource ‘ora.asm’ cannot be registered because its owner ‘root’ is not the same as the Oracle Restart user ‘oracle’.
>End Command output
2018-03-28 11:21:02: “upgrade model -s 11.2.0.4.0 -d 12.2.0.1.0 -p first” failed with status 1.
2018-03-28 11:21:02: Executing cmd: /app/gi/12201_grid/bin/clsecho -p has -f clsrsc -m 180 “/app/gi/12201_grid/bin/srvctl upgrade model -s 11.2.0.4.0 -d 12.2.0.1.0 -p first”
2018-03-28 11:21:02: Command

The rootupgrade.sh script is run as the root user as prescribed,  but root cannot add the ASM resource.
This leaves the installation unfinished.

There is no description in the Oracle Knowledge base, however according Oracle Support this problem is
caused by unpublished   Bug 25183818 : SIHA 11204 UPGRADE TO MAIN IS FAILING 

Patch 25183818 has be made available to fix this issue for Oracle 12.2.0.1. on Linux x86_64