Hello, everyone, I started seeing an issue over the weekend where one of my Samba servers that has been running fine for quite some time started seeing segfaults on the rpcd_lsad daemon, causing Winbind authentications to fail and, thus, SMB shares to be unavailable. The stack traces look like this: Stack trace of thread 1539: #0 0x00007ff1c61bca4f raise (libc.so.6) #1 0x00007ff1c618fdb5 abort (libc.so.6) #2 0x00007ff1c75b52c4 dump_core (libsmbconf.so.0) #3 0x00007ff1c75c2a70 smb_panic_s3 (libsmbconf.so.0) #4 0x00007ff1c7c31a1e smb_panic (/usr/lib64/libsamba-util.so.0.0.1) #5 0x00007ff1c797c405 set_unix_security_ctx (libsmbd-base-samba4.so) #6 0x00007ff1c797c61d set_sec_ctx_internal (libsmbd-base-samba4.so) #7 0x00007ff1c797cd3b set_root_sec_ctx (libsmbd-base-samba4.so) #8 0x00007ff1c7ada8c6 xid_to_sid (/usr/lib64/libsamba-passdb.so.0.28.0) #9 0x00007ff1c7adabeb gid_to_sid (/usr/lib64/libsamba-passdb.so.0.28.0) #10 0x00007ff1c7b6e189 add_local_groups (/usr/lib64/samba/libauth-samba4.so) #11 0x00007ff1c7b6f175 create_local_nt_token_from_info3 (/usr/lib64/samba/libauth-samba4.so) #12 0x00007ff1c7b683af create_local_token.part.2 (/usr/lib64/samba/libauth-samba4.so) #13 0x00007ff1c7b6a187 make_new_session_info_guest.constprop.6 (/usr/lib64/samba/libauth-samba4.so) #14 0x00007ff1c7b6a470 init_guest_session_info (/usr/lib64/samba/libauth-samba4.so) #15 0x00007ff1c7ca629d rpc_worker_main (/usr/lib64/samba/libRPC-WORKER-samba4.so) #16 0x000056236e8e6a90 main (rpcd_lsad) #17 0x00007ff1c61a8ca3 __libc_start_main (libc.so.6) #18 0x000056236e8e6ace _start (rpcd_lsad) In troubleshooting the issue, I disabled SELinux on the system, and the issue seems to have gone away - it's just strange that it showed up seemingly out of nowhere. I also have other systems running Samba with SELinux enabled, and haven't seen those issues pop up anywhere else (yet). Environment is: * CentOS Stream 8 * 4.18.0-394.el8.x86_64 * Samba 4.16.2 * Active Directory at functional level 2012, with 2012-2019 servers Anyone seen any similar issues, or any hints as to what may be going on? Let me know if I can provide any more detail. -Nick