Re: UPDATE on Domain Array that is based on a composite key crashes - Mailing list pgsql-hackers

On Tue, Oct 19, 2021 at 12:39 AM Onder Kalaci <onderk@microsoft.com> wrote:

Hi hackers,

 

I couldn’t find a similar report to this one, so starting a new thread. I can reproduce this on v14.0 as well as PostgreSQL 12.5 (not tried below versions).

 

Steps to reproduce:

 

CREATE TYPE two_ints as (if1 int, if2 int);

CREATE DOMAIN domain AS two_ints CHECK ((VALUE).if1 > 0);

CREATE TABLE domain_indirection_test (f1 int, f3 domain, domain_array domain[]);

INSERT INTO domain_indirection_test (f1,f3.if1) VALUES (0, 1);

UPDATE domain_indirection_test SET domain_array[0].if2 = 5;

server closed the connection unexpectedly

                This probably means the server terminated abnormally

                before or while processing the request.

The connection to the server was lost. Attempting reset: Failed.

Time: 3.990 ms

@:-!>

 

 

The backtrace on PG 12.5 (As far as I remember, PG14 looks very similar) :

 

(lldb) bt

* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x0)

  * frame #0: 0x00000001036584b7 postgres`pg_detoast_datum(datum=0x0000000000000000) at fmgr.c:1741:6

    frame #1: 0x0000000103439a86 postgres`ExecEvalFieldStoreDeForm(state=<unavailable>, op=0x00007f9212045df8, econtext=<unavailable>) at execExprInterp.c:3025:12

    frame #2: 0x000000010343834e postgres`ExecInterpExpr(state=<unavailable>, econtext=<unavailable>, isnull=0x00007ffeec91fdc7) at execExprInterp.c:1337:4

    frame #3: 0x000000010343742b postgres`ExecInterpExprStillValid(state=0x00007f921181db18, econtext=0x00007f921181d670, isNull=<unavailable>) at execExprInterp.c:1778:9

    frame #4: 0x0000000103444e0d postgres`ExecEvalExprSwitchContext(state=0x00007f921181db18, econtext=0x00007f921181d670, isNull=<unavailable>) at executor.h:310:13

    frame #5: 0x0000000103444cf0 postgres`ExecProject(projInfo=0x00007f921181db10) at executor.h:344:9

    frame #6: 0x0000000103444af6 postgres`ExecScan(node=0x00007f921181d560, accessMtd=(postgres`SeqNext at nodeSeqscan.c:51), recheckMtd=(postgres`SeqRecheck at nodeSeqscan.c:90)) at execScan.c:239:12

    frame #7: 0x0000000103461d17 postgres`ExecSeqScan(pstate=<unavailable>) at nodeSeqscan.c:112:9

    frame #8: 0x000000010344375c postgres`ExecProcNodeFirst(node=0x00007f921181d560) at execProcnode.c:445:9

    frame #9: 0x000000010345eefe postgres`ExecProcNode(node=0x00007f921181d560) at executor.h:242:9

    frame #10: 0x000000010345e74f postgres`ExecModifyTable(pstate=0x00007f921181d090) at nodeModifyTable.c:2079:14

    frame #11: 0x000000010344375c postgres`ExecProcNodeFirst(node=0x00007f921181d090) at execProcnode.c:445:9

    frame #12: 0x000000010343f25e postgres`ExecProcNode(node=0x00007f921181d090) at executor.h:242:9

    frame #13: 0x000000010343d80d postgres`ExecutePlan(estate=0x00007f921181cd10, planstate=0x00007f921181d090, use_parallel_mode=<unavailable>, operation=CMD_UPDATE, sendTuples=false, numberTuples=0, direction=ForwardScanDirection, dest=0x00007f9211818c38, execute_once=<unavailable>) at execMain.c:1646:10

    frame #14: 0x000000010343d745 postgres`standard_ExecutorRun(queryDesc=0x00007f921180e310, direction=ForwardScanDirection, count=0, execute_once=true) at execMain.c:364:3

    frame #15: 0x000000010343d67c postgres`ExecutorRun(queryDesc=0x00007f921180e310, direction=ForwardScanDirection, count=0, execute_once=<unavailable>) at execMain.c:308:3

    frame #16: 0x00000001035784a8 postgres`ProcessQuery(plan=<unavailable>, sourceText=<unavailable>, params=<unavailable>, queryEnv=0x0000000000000000, dest=<unavailable>, completionTag="") at pquery.c:161:2

    frame #17: 0x0000000103577c5e postgres`PortalRunMulti(portal=0x00007f9215024110, isTopLevel=true, setHoldSnapshot=false, dest=0x00007f9211818c38, altdest=0x00007f9211818c38, completionTag="") at pquery.c:0

    frame #18: 0x000000010357763d postgres`PortalRun(portal=0x00007f9215024110, count=9223372036854775807, isTopLevel=<unavailable>, run_once=<unavailable>, dest=0x00007f9211818c38, altdest=0x00007f9211818c38, completionTag="") at pquery.c:796:5

    frame #19: 0x0000000103574f87 postgres`exec_simple_query(query_string="UPDATE domain_indirection_test SET domain_array[0].if2 = 5;") at postgres.c:1215:10

    frame #20: 0x00000001035746b8 postgres`PostgresMain(argc=<unavailable>, argv=<unavailable>, dbname=<unavailable>, username=<unavailable>) at postgres.c:0

    frame #21: 0x000000010350d712 postgres`BackendRun(port=<unavailable>) at postmaster.c:4494:2

    frame #22: 0x000000010350cffa postgres`BackendStartup(port=<unavailable>) at postmaster.c:4177:3

    frame #23: 0x000000010350c59c postgres`ServerLoop at postmaster.c:1725:7

    frame #24: 0x000000010350ac8d postgres`PostmasterMain(argc=3, argv=0x00007f9210d049c0) at postmaster.c:1398:11

    frame #25: 0x000000010347fbdd postgres`main(argc=<unavailable>, argv=<unavailable>) at main.c:228:3

    frame #26: 0x00007fff204e8f3d libdyld.dylib`start + 1

 

 

Thanks,

Onder KALACI

Software Engineer at Microsoft &

Developing the Citus database extension for PostgreSQL

 Hi,

 It seems the following change would fix the crash:

diff --git a/src/postgres/src/backend/executor/execExprInterp.c b/src/postgres/src/backend/executor/execExprInterp.c
index 622cab9d4..50cb4f014 100644
--- a/src/postgres/src/backend/executor/execExprInterp.c
+++ b/src/postgres/src/backend/executor/execExprInterp.c
@@ -3038,6 +3038,9 @@ ExecEvalFieldStoreDeForm(ExprState *state, ExprEvalStep *op, ExprContext *econte
         HeapTupleHeader tuphdr;
         HeapTupleData tmptup;

+        if (DatumGetPointer(tupDatum) == NULL) {
+            return;
+        }
         tuphdr = DatumGetHeapTupleHeader(tupDatum);
         tmptup.t_len = HeapTupleHeaderGetDatumLength(tuphdr);
         ItemPointerSetInvalid(&(tmptup.t_self));

Here is the result after the update statement:

# UPDATE domain_indirection_test SET domain_array[0].if2 = 5;
UPDATE 1
# select * from domain_indirection_test;
 f1 |  f3  |  domain_array
----+------+----------------
  0 | (1,) | [0:0]={"(,5)"}
(1 row)

Cheers