Segmentation fault in PostgreSQL 17.7 during REINDEX TABLE CONCURRENTLY

Hello,

While running a REINDEX TABLE CONCURRENTLY on a table indexes in a PostgreSQL 17.7 database, we got the following error:
2026-03-17 18:19:55.244 WAT [2261667] LOG: server process (PID 2382873) was terminated by signal 11: Segmentation fault
2026-03-17 18:19:55.244 WAT [2261667] DETAIL: Failed process was running: REINDEX TABLE CONCURRENTLY sibs.purchases;
2026-03-17 18:19:55.244 WAT [2261667] LOG: terminating any other active server processes
2026-03-17 18:19:55.257 WAT [2261667] LOG: all server processes terminated; reinitializing
2026-03-17 18:19:55.354 WAT [2382972] LOG: database system was interrupted; last known up at 2026-03-17 18:18:58 WAT
2026-03-17 18:19:55.449 WAT [2382972] LOG: database system was not properly shut down; automatic recovery in progress
2026-03-17 18:19:55.457 WAT [2382972] LOG: redo starts at 310/8142BEC0
2026-03-17 18:19:56.352 WAT [2382972] LOG: invalid record length at 310/988BAA18: expected at least 24, got 0
2026-03-17 18:19:56.352 WAT [2382972] LOG: redo done at 310/988BA9E0 system usage: CPU: user: 0.28 s, system: 0.34 s, elapsed: 0.89 s
2026-03-17 18:19:56.360 WAT [2382973] LOG: checkpoint starting: end-of-recovery immediate wait

This is the coredump associated with error.
PID: 2382873 (postgres)
UID: 26 (postgres)
GID: 26 (postgres)
Signal: 11 (SEGV)
Timestamp: Tue 2026-03-17 18:19:53 WAT (16h ago)
Command Line: postgres: postgres easysms_restore_250226 [local] REINDEX
Executable: /usr/pgsql-17/bin/postgres
Control Group: /system.slice/postgresql-17.service
Unit: postgresql-17.service
Slice: system.slice
Boot ID: 0a323ad20fcf403791a46425b08245f6
Machine ID: 9db3f77eadaf498bab9ee45abb0ba721
Hostname: cerstidbtstc
Storage: /var/lib/systemd/coredump/core.postgres.26.0a323ad20fcf403791a46425b08245f6.2382873.1773767993000000.lz4
Message: Process 2382873 (postgres) of user 26 dumped core.

Stack trace of thread 2382873:
#0 0x00000000005d67a8 validate_index_callback (postgres)
#1 0x00000000005738bd btvacuumpage (postgres)
#2 0x0000000000573d8a btvacuumscan (postgres)
#3 0x0000000000573f00 btbulkdelete (postgres)
#4 0x00000000005d9873 validate_index (postgres)
#5 0x000000000066b583 ReindexRelationConcurrently.isra.1 (postgres)
#6 0x000000000066c784 ExecReindex (postgres)
#7 0x0000000000870d2f ProcessUtilitySlow.isra.5 (postgres)
#8 0x000000000086fa60 standard_ProcessUtility (postgres)
#9 0x000000000086e4cf PortalRunUtility (postgres)
#10 0x000000000086e603 PortalRunMulti (postgres)
#11 0x000000000086eb5b PortalRun (postgres)
#12 0x000000000086adab exec_simple_query (postgres)
#13 0x000000000086c598 PostgresMain (postgres)
#14 0x00000000008672b5 BackendMain (postgres)
#15 0x00000000007d850f postmaster_child_launch (postgres)
#16 0x00000000007dbe5c ServerLoop (postgres)
#17 0x00000000007dda78 PostmasterMain (postgres)
#18 0x000000000050f843 main (postgres)
#19 0x00007f91323277c3 __libc_start_main (libc.so.6)
#20 0x000000000050fe1e _start (postgres)

We were able to run the REINDEX TABLE CONCURRENTLY successfully multiple times, so it doesn't happen in every execution of the REINDEX.

Cumprimentos,

Ana Almeida
Consultant
AMS - Advanced Managed Services
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