smbd segfaults in kerberos when attempting join a domain with libreSSL as the SSL implementation:
fca38752 OBJ_add_object (81e2f68, 814f918, 6, fcb08932, fcb08940, 81e2f68) + 22

fca39503 OBJ_create (fcb08924, fcb08932, fcb08940, fcaf8c3b, fcb1a484, 0) + e3

fcaf8cb0 pkinit_init_pkinit_oids (819a0c8, 0, 34, fcb03f6c, 1, 18) + 6b

fcafcd8f pkinit_init_plg_crypto (813056c, 0, 10, feb06db9, f8, 0) + 52

fcaf7965 pkinit_client_plugin_init (8090048, fd7d9a0c, f0, 80900f8, fd7d9a0c, 1) + 92

fccd58be krb5_init_preauth_context (8090048, 8130598, fccf663d, fcd0a000, fcd0a000, 8090048) + 1e0

fccd5c70 krb5_preauth_request_context_init (8090048, fd7d9b74, f, 8130598, 6, fccf663d) + 29

fccc9c9f krb5_get_init_creds (8090048, fd7daa28, 812fdf8, 0, 0, 0) + 42d

fccd33c0 __krb5_get_init_creds_password (8090048, fd7daa28, 812fdf8, fd7db5cd, 0, 0) + 14c

fccd38a6 krb5_get_init_creds_password (8090048, fd7daa28, 812fdf8, fd7db5cd, 0, 0) + 5e

fec5d947 smb_kinit (fd7db054, fd7db5a4, fd7db5cd, fe58b000, 8090048, fe6c0059) + 1b8

fec58086 smb_ads_open_main (fd7dadd0, fd7db054, fd7db5a4, fd7db5cd, 0, 4) + 42

fec588e0 smb_ads_join (fd7db054, fd7db5a4, fd7db5cd, fd7db29a, 0, 0) + a4

fe6d1448 mlsvc_join (fd7db4a4, fd7db39c, fd7db4a4, fd7db4a4, fd7db4a4, fd7db6b4) + 22f

0805a9e4 smbd_join_domain (fd7db4a4, fd7db39c, 0, fd7db4a4, fd7db6b4, 0) + 33

0805ab48 smbd_join (fd7db4a4, fd7db39c, 8056e60, fd7db4a4, fece0018, fece08e8) + 39

080596b7 smbd_dop_join (fd7db6b4, fed281ec, 12, fed281f7, 24, 24) + 7d

08059e74 smbd_door_dispatch_op (fd7db6b4, fd7db734, 24, 0, 0, 0) + 5c

0805a3d5 smbd_door_dispatch (80718c0, fd7db734, 6cc, 0, 0, 805a22f) + 1a6

feec6c2b __door_return () + 4b
The issue was fixed by backporting these changes to MIT Kerberos:

https://github.com/krb5/krb5/commit/8ee1790ba6e3468d7ed53ed46123dc9545a4216f

https://github.com/krb5/krb5/commit/6b9e570a7e98470b806a26c5119e53b2145e2586

With the patch applied smbd no longer segfaults when attempting to join a domain.
This fix has been in production for over two years without issue.