run_commands_on_session_level_connection_to_node causes invalid memory read

[onurctirtir]

Not a release blocker, but still needs to be fixed to avoid crashing during isolation testing.

+++++++++++++++++++++++++ citus_valgrind_test_log.txt.23793 +++++++++++++++++++++++++
==23793== VALGRINDERROR-BEGIN
==23793== Invalid read of size 8
==23793== at 0x75425DA: CitusPQFinish (citus/src/backend/distributed/connection/connection_management.c:1235)
==23793== by 0x7542F49: CloseConnection (citus/src/backend/distributed/connection/connection_management.c:710)
==23793== by 0x75EC4BF: stop_session_level_connection_to_node (citus/src/backend/distributed/test/run_from_same_connection.c:223)
==23793== by 0x419699: ExecInterpExpr (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:926)
==23793== by 0x4151C2: ExecInterpExprStillValid (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:2299)
==23793== by 0x458D83: ExecEvalExprNoReturn (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:419)
==23793== by 0x458DC2: ExecEvalExprNoReturnSwitchContext (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:460)
==23793== by 0x458E00: ExecProject (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:492)
==23793== by 0x458ED3: ExecResult (pgenv/src/postgresql-18.1/src/backend/executor/nodeResult.c:135)
==23793== by 0x427196: ExecProcNodeFirst (pgenv/src/postgresql-18.1/src/backend/executor/execProcnode.c:469)
==23793== by 0x41E425: ExecProcNode (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:315)
==23793== by 0x41E4D5: ExecutePlan (pgenv/src/postgresql-18.1/src/backend/executor/execMain.c:1707)
==23793== Address 0x7194df8 is 3,208 bytes inside a recently re-allocated block of size 8,192 alloc'd
==23793== at 0x4846828: malloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==23793== by 0x7AB13A: AllocSetContextCreateInternal (pgenv/src/postgresql-18.1/src/backend/utils/mmgr/aset.c:444)
==23793== by 0x75427BF: InitializeConnectionManagement (citus/src/backend/distributed/connection/connection_management.c:108)
==23793== by 0x750EA67: _PG_init (citus/src/backend/distributed/shared_library_init.c:519)
==23793== by 0x7891C7: internal_load_library (pgenv/src/postgresql-18.1/src/backend/utils/fmgr/dfmgr.c:299)
==23793== by 0x7899B9: load_file (pgenv/src/postgresql-18.1/src/backend/utils/fmgr/dfmgr.c:161)
==23793== by 0x792B09: load_libraries (pgenv/src/postgresql-18.1/src/backend/utils/init/miscinit.c:1888)
==23793== by 0x794625: process_shared_preload_libraries (pgenv/src/postgresql-18.1/src/backend/utils/init/miscinit.c:1906)
==23793== by 0x57351D: PostmasterMain (pgenv/src/postgresql-18.1/src/backend/postmaster/postmaster.c:932)
==23793== by 0x482953: main (pgenv/src/postgresql-18.1/src/backend/main/main.c:227)
==23793==
==23793== VALGRINDERROR-END
==23793== VALGRINDERROR-BEGIN
==23793== Invalid read of size 1
==23793== at 0x76B3208: sendTerminateConn (pgenv/src/postgresql-18.1/src/interfaces/libpq/fe-connect.c:5226)
==23793== by 0x76B3A0B: pqClosePGconn (pgenv/src/postgresql-18.1/src/interfaces/libpq/fe-connect.c:5259)
==23793== by 0x76B3AA8: PQfinish (pgenv/src/postgresql-18.1/src/interfaces/libpq/fe-connect.c:5305)
==23793== by 0x75425EA: CitusPQFinish (citus/src/backend/distributed/connection/connection_management.c:1237)
==23793== by 0x7542F49: CloseConnection (citus/src/backend/distributed/connection/connection_management.c:710)
==23793== by 0x75EC4BF: stop_session_level_connection_to_node (citus/src/backend/distributed/test/run_from_same_connection.c:223)
==23793== by 0x419699: ExecInterpExpr (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:926)
==23793== by 0x4151C2: ExecInterpExprStillValid (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:2299)
==23793== by 0x458D83: ExecEvalExprNoReturn (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:419)
==23793== by 0x458DC2: ExecEvalExprNoReturnSwitchContext (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:460)
==23793== by 0x458E00: ExecProject (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:492)
==23793== by 0x458ED3: ExecResult (pgenv/src/postgresql-18.1/src/backend/executor/nodeResult.c:135)
==23793== Address 0x7f7f7f7f7f7f80ef is not stack'd, malloc'd or (recently) free'd
==23793==
==23793== VALGRINDERROR-END
==23793==
==23793== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==23793== General Protection Fault
==23793== at 0x76B3208: sendTerminateConn (pgenv/src/postgresql-18.1/src/interfaces/libpq/fe-connect.c:5226)
==23793== by 0x76B3A0B: pqClosePGconn (pgenv/src/postgresql-18.1/src/interfaces/libpq/fe-connect.c:5259)
==23793== by 0x76B3AA8: PQfinish (pgenv/src/postgresql-18.1/src/interfaces/libpq/fe-connect.c:5305)
==23793== by 0x75425EA: CitusPQFinish (citus/src/backend/distributed/connection/connection_management.c:1237)
==23793== by 0x7542F49: CloseConnection (citus/src/backend/distributed/connection/connection_management.c:710)
==23793== by 0x75EC4BF: stop_session_level_connection_to_node (citus/src/backend/distributed/test/run_from_same_connection.c:223)
==23793== by 0x419699: ExecInterpExpr (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:926)
==23793== by 0x4151C2: ExecInterpExprStillValid (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:2299)
==23793== by 0x458D83: ExecEvalExprNoReturn (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:419)
==23793== by 0x458DC2: ExecEvalExprNoReturnSwitchContext (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:460)
==23793== by 0x458E00: ExecProject (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:492)
==23793== by 0x458ED3: ExecResult (pgenv/src/postgresql-18.1/src/backend/executor/nodeResult.c:135

+++++++++++++++++++++++++ citus_valgrind_test_log.txt.24564 +++++++++++++++++++++++++
==24564== VALGRINDERROR-BEGIN
==24564== Invalid read of size 8
==24564== at 0x75460E0: SendRemoteCommand (citus/src/backend/distributed/connection/remote_commands.c:558)
==24564== by 0x7546512: ExecuteOptionalRemoteCommand (citus/src/backend/distributed/connection/remote_commands.c:480)
==24564== by 0x75EC0FF: GetRemoteProcessId (citus/src/backend/distributed/test/run_from_same_connection.c:243)
==24564== by 0x75EC3AE: run_commands_on_session_level_connection_to_node (citus/src/backend/distributed/test/run_from_same_connection.c:168)
==24564== by 0x41977C: ExecInterpExpr (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:977)
==24564== by 0x4151C2: ExecInterpExprStillValid (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:2299)
==24564== by 0x458D83: ExecEvalExprNoReturn (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:419)
==24564== by 0x458DC2: ExecEvalExprNoReturnSwitchContext (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:460)
==24564== by 0x458E00: ExecProject (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:492)
==24564== by 0x458ED3: ExecResult (pgenv/src/postgresql-18.1/src/backend/executor/nodeResult.c:135)
==24564== by 0x427196: ExecProcNodeFirst (pgenv/src/postgresql-18.1/src/backend/executor/execProcnode.c:469)
==24564== by 0x41E425: ExecProcNode (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:315)
==24564== Address 0x7194418 is 680 bytes inside a recently re-allocated block of size 8,192 alloc'd
==24564== at 0x4846828: malloc (in /usr/libexec/valgrind/vgpreload_memcheck-amd64-linux.so)
==24564== by 0x7AB13A: AllocSetContextCreateInternal (pgenv/src/postgresql-18.1/src/backend/utils/mmgr/aset.c:444)
==24564== by 0x75427BF: InitializeConnectionManagement (citus/src/backend/distributed/connection/connection_management.c:108)
==24564== by 0x750EA67: _PG_init (citus/src/backend/distributed/shared_library_init.c:519)
==24564== by 0x7891C7: internal_load_library (pgenv/src/postgresql-18.1/src/backend/utils/fmgr/dfmgr.c:299)
==24564== by 0x7899B9: load_file (pgenv/src/postgresql-18.1/src/backend/utils/fmgr/dfmgr.c:161)
==24564== by 0x792B09: load_libraries (pgenv/src/postgresql-18.1/src/backend/utils/init/miscinit.c:1888)
==24564== by 0x794625: process_shared_preload_libraries (pgenv/src/postgresql-18.1/src/backend/utils/init/miscinit.c:1906)
==24564== by 0x57351D: PostmasterMain (pgenv/src/postgresql-18.1/src/backend/postmaster/postmaster.c:932)
==24564== by 0x482953: main (pgenv/src/postgresql-18.1/src/backend/main/main.c:227)
==24564==
==24564== VALGRINDERROR-END
==24564== VALGRINDERROR-BEGIN
==24564== Invalid read of size 4
==24564== at 0x76B3DA1: PQstatus (pgenv/src/postgresql-18.1/src/interfaces/libpq/fe-connect.c:7579)
==24564== by 0x75460F8: SendRemoteCommand (citus/src/backend/distributed/connection/remote_commands.c:566)
==24564== by 0x7546512: ExecuteOptionalRemoteCommand (citus/src/backend/distributed/connection/remote_commands.c:480)
==24564== by 0x75EC0FF: GetRemoteProcessId (citus/src/backend/distributed/test/run_from_same_connection.c:243)
==24564== by 0x75EC3AE: run_commands_on_session_level_connection_to_node (citus/src/backend/distributed/test/run_from_same_connection.c:168)
==24564== by 0x41977C: ExecInterpExpr (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:977)
==24564== by 0x4151C2: ExecInterpExprStillValid (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:2299)
==24564== by 0x458D83: ExecEvalExprNoReturn (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:419)
==24564== by 0x458DC2: ExecEvalExprNoReturnSwitchContext (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:460)
==24564== by 0x458E00: ExecProject (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:492)
==24564== by 0x458ED3: ExecResult (pgenv/src/postgresql-18.1/src/backend/executor/nodeResult.c:135)
==24564== by 0x427196: ExecProcNodeFirst (pgenv/src/postgresql-18.1/src/backend/executor/execProcnode.c:469)
==24564== Address 0x7f7f7f7f7f7f8177 is not stack'd, malloc'd or (recently) free'd
==24564==
==24564== VALGRINDERROR-END
==24564==
==24564== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==24564== General Protection Fault
==24564== at 0x76B3DA1: PQstatus (pgenv/src/postgresql-18.1/src/interfaces/libpq/fe-connect.c:7579)
==24564== by 0x75460F8: SendRemoteCommand (citus/src/backend/distributed/connection/remote_commands.c:566)
==24564== by 0x7546512: ExecuteOptionalRemoteCommand (citus/src/backend/distributed/connection/remote_commands.c:480)
==24564== by 0x75EC0FF: GetRemoteProcessId (citus/src/backend/distributed/test/run_from_same_connection.c:243)
==24564== by 0x75EC3AE: run_commands_on_session_level_connection_to_node (citus/src/backend/distributed/test/run_from_same_connection.c:168)
==24564== by 0x41977C: ExecInterpExpr (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:977)
==24564== by 0x4151C2: ExecInterpExprStillValid (pgenv/src/postgresql-18.1/src/backend/executor/execExprInterp.c:2299)
==24564== by 0x458D83: ExecEvalExprNoReturn (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:419)
==24564== by 0x458DC2: ExecEvalExprNoReturnSwitchContext (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:460)
==24564== by 0x458E00: ExecProject (pgenv/src/postgresql-18.1/src/backend/executor/../../../src/include/executor/executor.h:492)
==24564== by 0x458ED3: ExecResult (pgenv/src/postgresql-18.1/src/backend/executor/nodeResult.c:135)
==24564== by 0x427196: ExecProcNodeFirst (pgenv/src/postgresql-18.1/src/backend/executor/execProcnode.c:469)