Geert Hendrickx wrote:

Hi

Shortly after upgrading from OpenLDAP 2.6.13 to 2.6.15 (from Symas repo on RHEL 8), we are seeing malloc crashes:

Sep 16 12:08:24 slapd[2358763]: free(): invalid pointer Sep 16 13:40:52 slapd[2377743]: malloc(): unaligned tcache chunk detected Sep 16 13:50:51 slapd[2416163]: double free or corruption (out)

Sep 16 12:23:04 slapd[2379983]: malloc(): unaligned tcache chunk detected Sep 16 12:48:31 slapd[2401167]: malloc(): unaligned tcache chunk detected Sep 16 13:24:48 slapd[2400058]: malloc(): unaligned fastbin chunk detected

We rolled back for now, what can we provide to help debug this?

gdb stack traces might help, but it would probably be most enlightening if you can give us a test case that reproduces the issue. Running slapd under valgrind should also give more insight into the problem.