Distributed Transaction Fails using database link

Symptoms: When having a transaction with database link involved, it results in an error that says:
ORA-03150: end-of-file on communication channel for database link
ORA-02055: distributed update operation failed; rollback required
ORA-02063: preceding lines from DBLINK_NAME.

Perhaps you already have checked the database link if its working and no problem, it returns data, but on your procedure or package dont.

Cause: This is a bug that happens on Oracle 11.2.0.4 and later.
It is reported with more details on the Doc ID:
(Doc ID 1909692.1) Distributed Transaction Fails with ORA-03150 ORA-02055, alert log shows ORA-07445: [qsmmixGetIdxKeyStats()+231]

Solution: As it is mentioned on the Oracle Support, there is a patch that fixes the bug.
Apply that using the instructions given with the patch.

- For Non-RAC Environments (Standalone Databases): 
$ opatch apply online -connectString <SID>:<USERNAME>:<PASSWORD>:
- For RAC Environments:
$ opatch apply online -connectString <SID_Node1>:<Username_Node1>:<Password_Node1>:<Node1_Name>,<SID_Node2>:<Username_Node2>:<Password_Node2>:<Node2_Name>,<SID_NodeN>:<Username_NodeN>:<Password_NodeN>:<NodeN_Name>