libc segfault in OpenLDAP on guest after upgrade to Proxmox 8


New Member
Sep 15, 2023
After upgrading to Proxmox 8, running 6.2.16-12-pve, a guest running slapd (OpenLdap) experiences segfaults of this service

Message below is after upgrading to the guest to Debian Bookworm (Linux jupiter 6.1.0-12-amd64 #1 SMP PREEMPT_DYNAMIC Debian 6.1.52-1 (2023-09-07) x86_64 GNU/Linux)

2023-09-15T11:50:53.780941+01:00 jupiter kernel: [  950.129323] slapd[1036]: segfault at 1 ip 00007fb398dc60d4 sp 00007fb325be96a0 error 6 in[7fb398d06000+155000] likely on CPU 1 (core 1, socket 0)

The segfault has been seen on 2 hosts in a three host cluster, both running Opteron 6380 CPUs. Guest is configured with 1 socket, 2 cores, CPU set to 'host'.
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Thank you @BobhWasatch actually coincidentally I did see that there was a pending amd-microcode update on the hosts which might help (Debian have split the non-free repo in two and I hadn't added non-free-firmware). Will keep an eye and feed back if it fixes the problem.
@BobhWasatch early days but we've not seen the segfault since updating the microcode.

Short summary in case anyone comes across this thread:

- Debian bookworm repositories split out the non-free-firmware from the generic non-free section, requiring a modification to the /etc/apt/sources.list over and above simply changing the distribution version from bullseye to bookworm
- Without adding non-free-firmware, a pending amd microcode (and probably intel microcode is the same) was not installed during the upgrade from Proxmox 7 to 8
- The fix is to add non-free-firmware to the end of the sources.list entry (entries?) and run an apt update/upgrade
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