Some time ago, I attempted to apply a patch to upgrade my 2-node Oracle RAC Grid Infrastructure from version 19.24 to 19.27. However, I encountered the following error:

SEVERE [1] com.oracle.glcm.patch.auto.OPatchAuto – OPatchAuto failed.
> com.oracle.glcm.patch.auto.OPatchAutoException: OPATCHAUTO-72043: Patch collection failed.
> OPATCHAUTO-72043: Failed to create bundle patch object.
> OPATCHAUTO-72043: Please verify the patch supplied.
> at com.oracle.glcm.patch.auto.db.integration.model.plan.PatchingProcessInitializer.initializePatchPackageBag(PatchingProcessInitializer.java:97)
> at com.oracle.glcm.patch.auto.db.integration.model.plan.PatchingProcessInitializer.processInit(PatchingProcessInitializer.java:66)
> at com.oracle.glcm.patch.auto.db.integration.model.productsupport.DBCommonSupport.initializePatchData(DBCommonSupport.java:126)
> at com.oracle.glcm.patch.auto.db.integration.model.productsupport.DBBaseProductSupport.initializePatchData(DBBaseProductSupport.java:442)
> at com.oracle.glcm.patch.auto.db.integration.model.productsupport.DBCommonSupport.loadTopology(DBCommonSupport.java:163)
> at com.oracle.glcm.patch.auto.db.integration.model.productsupport.DBBaseProductSupport.loadTopology(DBBaseProductSupport.java:214)
> at com.oracle.glcm.patch.auto.db.integration.model.productsupport.DBProductSupport.loadTopology(DBProductSupport.java:69)
> at com.oracle.glcm.patch.auto.OPatchAuto.loadTopology(OPatchAuto.java:1735)
> at com.oracle.glcm.patch.auto.OPatchAuto.prepareOrchestration(OPatchAuto.java:733)
> at com.oracle.glcm.patch.auto.OPatchAuto.orchestrate(OPatchAuto.java:397)
> at com.oracle.glcm.patch.auto.OPatchAuto.orchestrate(OPatchAuto.java:344)
> at com.oracle.glcm.patch.auto.OPatchAuto.main(OPatchAuto.java:212)
> Caused by: com.oracle.glcm.patch.auto.db.integration.model.productsupport.patch.PatchCollectionException:  
> at com.oracle.glcm.patch.auto.db.framework.core.patch.OPatchSingletonPatchValidatorAndGenerator.generate(OPatchSingletonPatchValidatorAndGenerator.java:151)
> at oracle.dbsysmodel.patchsdk.PatchFactory.getInstance(PatchFactory.java:246)
> at com.oracle.glcm.patch.auto.db.framework.core.patch.impl.PatchPackageFactoryImpl.getPatchPackageFromDir(PatchPackageFactoryImpl.java:75)
> at com.oracle.glcm.patch.auto.db.product.patch.BundlePatchObject.prcoessPatch(BundlePatchObject.java:131)
> at com.oracle.glcm.patch.auto.db.product.patch.BundlePatchObject.createPatchBagForPatchLocation(BundlePatchObject.java:124)
> at com.oracle.glcm.patch.auto.db.product.patch.BundlePatchObject.<init>(BundlePatchObject.java:77)
> at com.oracle.glcm.patch.auto.db.integration.model.productsupport.patch.PatchInformationInitializer.createPatch(PatchInformationInitializer.java:43)
> at com.oracle.glcm.patch.auto.db.integration.model.plan.PatchingProcessInitializer.initializePatchPackageBag(PatchingProcessInitializer.java:80)
> … 11 more

I removed the existing OPatch directory, unzipped the new OPatch as the grid user, and moved it to $GRID_HOME as the root user, but the problem still persisted. I then downloaded the software again and used p6880880_190000_12.2.0.1.45_Linux-x86-64.zip, but the issue remained unresolved.

Further i noticed the below error :

Based on the analysis, we observed that the session is being terminated immediately after attempting to execute the following command using /bin/su as the grid user:

2025-06-03 10:16:44,379 INFO [1] com.oracle.glcm.patch.auto.db.product.executor.GISystemCall – System Call command is:
[/bin/su, grid, -m, -c, /u01/app/19.0.0/grid/perl/bin/perl /u01/app/19.0.0/grid/OPatch/auto/database/bin/OPatchAutoBinary.pl query patchinfo -patch_location /u01/orainst/19.27/grid/37641958/37642901 -result /u01/app/19.0.0/grid/OPatch/auto/dbtmp/result.ser]

Shortly after execution, the following error is returned:

2025-06-03 10:16:50,844 INFO [1] com.oracle.glcm.patch.auto.db.product.executor.GISystemCall – Error message:
Session terminated, killing shell… …killed.

2025-06-03 10:16:50,845 INFO [1] com.oracle.glcm.patch.auto.db.product.executor.GISystemCall – Return code: 131

Upon further analysis, we discovered that core dumps were continuously being generated, and it was observed that the root user was terminating the shell initiated by the grid user. We identified that this behavior was due to restrictions placed on the grid user in the PAM (Pluggable Authentication Module) configuration. After removing these restrictions from the PAM configuration, the issue was resolved and the patching completed successfully.