APAR status
Closed as program error.
Error description
A select statement is run by some user without errors and is inserted into the statement cache. Then a second user runs the same statement. But this user does not have select permission for all columns in the projection list. This leads to error: -272 No SELECT permission. as expected. But in addition the ref_cnt for the statement in the cache becomes negative (onstat -g ssc): lru hash ref_cnt hits flag heap_ptr database user ---------------------------------------------------------------- ----- 0 272 -1 1 -F 154dcc038 d usr1 select k from t1 If a sufficiently privileged user runs the statement again, the ref_cnt is increased to 0 while the statement is in use. As a consequence it can be bumped out of that cache and it's memory can be reused by another statement during that time. This results in an engine crash. There is no typical stack trace. At the time of the crash most information about the statement (like it's text) is wiped out.
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: * * Users with STMT_CACHE enabled and having specific column * * level privileges granted to users * **************************************************************** * PROBLEM DESCRIPTION: * * Users with STMT_CACHE enabled can get into memory corruption * * related issues if they have specific column level privilege * * granted to some user and that user tries to select the * * column that he is not granted permission to select. * * * * Also, the same issue can occur if a temp table is created * * with some name, and later a permanent table is created with * * the same name, and the select of the permanent table resides * * in the statement cache, and the same select statement is run * * on the temp table. * **************************************************************** * RECOMMENDATION: * * Upgrade to 11.50.xC7 and above. * ****************************************************************
Problem conclusion
Fixed in 11.50.xC7
Temporary fix
Comments
APAR Information
APAR number
IC66047
Reported component name
IBM IDS ENTRP E
Reported component ID
5724L2304
Reported release
B15
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2010-02-03
Closed date
2010-10-01
Last modified date
2010-10-01
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
IBM IDS ENTRP E
Fixed component ID
5724L2304
Applicable component levels
RB15 PSY
UP
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Document Information
Modified date:
01 October 2010