A fix is available
APAR status
Closed as program error.
Error description
A GET CONTAINER command was issued from an application with an invalid FLENGTH parameter. This invalid FLENGTH caused overlays of lots of storage including pages of CICS control blocks and leading/trailing check zones for task storage areas. Page faults in MVS system trace show module DFHEIBAM accessing the overlaid pages. DFHEIBAM tries to detect bad pointers and lengths before moving any storage by 'touching' each page within the range of the INTO parameter + FLENGTH specified on the GET CONTAINER command. If an 0C4 occurs, CICS will convert the error into an abend AEYF for the task. However, this has not happened because each page touched by DFHEIBAM within the range of INTO+FLENGTH is both GETMAINed and accessible in CICS key. So even with Storage Protection turned on, no 0C4 or AEYF occurs, the GET CONTAINER request completes normally, and lots of storage is overlaid. CICS then issues storage violations (DFHSM0102 message) and program checks for various components. CICS should improve its checking to try and avoid overlays of storage when bad pointers/lengths are passed on a GET CONTAINER command. Additional Symptom(s) Search Keyword(s): 0C4 S0C4 abend0C4 DFHAP0001 DFHSR0001 PUT CONTAINER unpredictible errors KIXREVxxx
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All CICS users. * **************************************************************** * PROBLEM DESCRIPTION: An application using GET CONTAINER INTO * * with an invalid FLENGTH value causes a * * large overlay of CICS storage with * * unpredictable results. * **************************************************************** Access to the GET CONTAINER INTO area is checked by CICS prior to moving any data but this is done running in CICS key. Applications running in USER key should not be permitted to address CICS key storage as part of the GET CONTAINER INTO area. Applications may be overlaying CICS Key storage in this way, and yet errors may not be apparent. These applications should be abended AEYF. Keywords: DFHEIBAM ABENDAEYF
Problem conclusion
DFHEIBAM will switch to run with the application's EXEC key before it checks to see if storage access is permitted. This will help to protect CICS storage when the application runs in user key with CICS storage protection active. Note that this APAR will not prevent GET CONTAINER INTO from invalidly moving data into CICS key storage unless the application runs in USER key.
Temporary fix
Comments
APAR Information
APAR number
PH24145
Reported component name
CICS TS Z/OS V5
Reported component ID
5655Y0400
Reported release
100
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt / Xsystem
Submitted date
2020-04-07
Closed date
2020-07-06
Last modified date
2020-08-03
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Modules/Macros
DFHEIBAM
Fix information
Fixed component name
CICS TS Z/OS V5
Fixed component ID
5655Y0400
Applicable component levels
R100 PSY UI70400
UP20/07/21 P F007
R200 PSY UI70401
UP20/07/09 P F007
R300 PSY UI70402
UP20/07/09 P F007
Fix is available
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Document Information
Modified date:
14 December 2020