Host hard-freezes with no logs on kernel 6.8.12-18-pve and forward, stable on kernel 6.8.12-16-pve, same hardware and workload, no BIOS change

[raketmotor]

Summary

Hard host freeze / lockup regression between 6.8.12-16-pve and newer kernels. System is stable on 6.8.12-16-pve but experiences complete hangs on 6.8.12-18-pve and 7.0.2-6-pve.

Environment
Proxmox VE: 9.2
Current kernel exhibiting issue: 7.0.2-6-pve
Previously affected kernel: 6.8.12-18-pve
Last known good kernel: 6.8.12-16-pve
NIC driver: igc
Network configuration:
vmbr0 Linux bridge
VLAN-aware bridge
Intel NIC (igc) attached to bridge
Host runs multiple VMs
Problem Description

The host experiences complete system hangs.

Symptoms during the failure:

Host stops responding to ping.
Host stops responding to SSH.
All VMs become unreachable.
Attached display goes black.
No new entries are written to the journal.
Recovery requires a hard power cycle.

The system does not appear to panic or reboot automatically.

Regression Evidence

I performed the following test:

Host was running a newer kernel and experienced periodic freezes.
I pinned kernel 6.8.12-16-pve.
After pinning 6.8.12-16-pve, the freezes completely disappeared.
No BIOS settings, hardware configuration, VM configuration, storage configuration, or network configuration changes were made.
After upgrading to Proxmox VE 9.2, which requires newer kernels, the freezes returned on 7.0.2-6-pve.

This strongly suggests a kernel regression introduced after 6.8.12-16-pve.

Additional Notes

I attempted to configure netconsole in order to capture kernel output during the freeze. However, netconsole appears incompatible with my current Proxmox bridge/firewall topology and could not be used successfully to capture crash output.

I am currently testing with:

nmi_watchdog=1 hardlockup_panic=1 softlockup_panic=1 panic=30

to determine whether the freeze can be converted into a panic and produce additional diagnostics.

Requested Assistance
Is this a known regression affecting kernels newer than 6.8.12-16-pve?
Are there known issues involving:
Intel igc driver
Linux bridge / VLAN-aware bridge networking
Proxmox VE 9.x kernels
Intel Alder Lake / N100 / N305 platforms (if applicable)
Are there recommended kernel parameters or debug options that could help identify the root cause?


System information

root@turing:~# pveversion -v
proxmox-ve: 9.2.0 (running kernel: 7.0.2-6-pve)
pve-manager: 9.2.2 (running version: 9.2.2/b9984c6d90a4bd80)
proxmox-kernel-helper: 9.1.0+fde2
proxmox-kernel-7.0: 7.0.2-6
proxmox-kernel-7.0.2-6-pve-signed: 7.0.2-6
amd64-microcode: 3.20250311.1
ceph-fuse: 19.2.3-pve4
corosync: 3.1.10-pve2
criu: 4.1.1-1
frr-pythontools: 10.6.1-1+pve2
ifupdown2: 3.3.0-1+pmx12
ksm-control-daemon: 1.5-1
libjs-extjs: 7.0.0-5
libproxmox-acme-perl: 1.7.1
libproxmox-backup-qemu0: 2.0.2
libproxmox-rs-perl: 0.4.1
libpve-access-control: 9.1.1
libpve-apiclient-perl: 3.4.2
libpve-cluster-api-perl: 9.1.5
libpve-cluster-perl: 9.1.5
libpve-common-perl: 9.1.12
libpve-guest-common-perl: 6.0.3
libpve-http-server-perl: 6.0.5
libpve-network-perl: 1.6.5
libpve-notify-perl: 9.1.5
libpve-rs-perl: 0.15.3
libpve-storage-perl: 9.1.5
libspice-server1: 0.15.2-1+b1
lvm2: 2.03.31-2+pmx1
lxc-pve: 7.0.0-2
lxcfs: 7.0.0-pve1
novnc-pve: 1.7.0-1
proxmox-backup-client: 4.2.0-1
proxmox-backup-file-restore: 4.2.0-1
proxmox-backup-restore-image: 1.0.0
proxmox-firewall: 1.2.3
proxmox-kernel-helper: 9.1.0+fde2
proxmox-mail-forward: 1.0.3
proxmox-mini-journalreader: 1.6
proxmox-offline-mirror-helper: 0.7.4
proxmox-widget-toolkit: 5.2.2
pve-cluster: 9.1.5
pve-container: 6.1.10
pve-docs: 9.2.1
pve-edk2-firmware: 4.2025.05-2
pve-esxi-import-tools: 1.0.1
pve-firewall: 6.0.4
pve-firmware: 3.18-3
pve-ha-manager: 5.2.4
pve-i18n: 3.7.4
pve-qemu-kvm: 11.0.0-3
pve-xtermjs: 6.0.0-1
qemu-server: 9.1.15
smartmontools: 7.5-pve2
spiceterm: 3.4.2
swtpm: 0.8.0+pve3
vncterm: 1.9.2
zfsutils-linux: 2.4.2-pve1

root@turing:~# uname -a
Linux turing 7.0.2-6-pve #1 SMP PREEMPT_DYNAMIC PMX 7.0.2-6 (2026-05-20T08:55Z) x86_64 GNU/Linux

root@turing:~# lscpu
Architecture: x86_64
CPU op-mode(s): 32-bit, 64-bit
Address sizes: 48 bits physical, 48 bits virtual
Byte Order: Little Endian
CPU(s): 16
On-line CPU(s) list: 0-15
Vendor ID: AuthenticAMD
Model name: AMD Ryzen 7 5700G with Radeon Graphics
CPU family: 25
Model: 80
Thread(s) per core: 2
Core(s) per socket: 8
Socket(s): 1
Stepping: 0
Frequency boost: enabled
CPU(s) scaling MHz: 81%
CPU max MHz: 4673.8232
CPU min MHz: 422.3340
BogoMIPS: 7599.68
Flags: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt pdpe1gb rdtscp lm constant_tsc rep_good nopl xtopology nonstop_tsc cpuid extd_apicid aperfmperf
rapl pni pclmulqdq monitor ssse3 fma cx16 sse4_1 sse4_2 x2apic movbe popcnt aes xsave avx f16c rdrand lahf_lm cmp_legacy svm extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit wdt tce topoext perfctr_core
perfctr_nb bpext perfctr_llc mwaitx cpb cat_l3 cdp_l3 hw_pstate ssbd mba ibrs ibpb stibp vmmcall fsgsbase bmi1 avx2 smep bmi2 erms invpcid cqm rdt_a rdseed adx smap clflushopt clwb sha_ni xsaveopt xsavec xgetbv1 xsaves cqm_
llc cqm_occup_llc cqm_mbm_total cqm_mbm_local user_shstk clzero irperf xsaveerptr rdpru wbnoinvd cppc arat npt lbrv svm_lock nrip_save tsc_scale vmcb_clean flushbyasid decodeassists pausefilter pfthreshold avic v_vmsave_vmlo
ad vgif v_spec_ctrl umip pku ospke vaes vpclmulqdq rdpid overflow_recov succor smca fsrm debug_swap
Virtualization features:
Virtualization: AMD-V
Caches (sum of all):
L1d: 256 KiB (8 instances)
L1i: 256 KiB (8 instances)
L2: 4 MiB (8 instances)
L3: 16 MiB (1 instance)
NUMA:
NUMA node(s): 1
NUMA node0 CPU(s): 0-15
Vulnerabilities:
Gather data sampling: Not affected
Ghostwrite: Not affected
Indirect target selection: Not affected
Itlb multihit: Not affected
L1tf: Not affected
Mds: Not affected
Meltdown: Not affected
Mmio stale data: Not affected
Old microcode: Not affected
Reg file data sampling: Not affected
Retbleed: Not affected
Spec rstack overflow: Mitigation; Safe RET
Spec store bypass: Mitigation; Speculative Store Bypass disabled via prctl
Spectre v1: Mitigation; usercopy/swapgs barriers and __user pointer sanitization
Spectre v2: Mitigation; Retpolines; IBPB conditional; IBRS_FW; STIBP always-on; RSB filling; PBRSB-eIBRS Not affected; BHI Not affected
Srbds: Not affected
Tsa: Mitigation; Clear CPU buffers
Tsx async abort: Not affected
Vmscape: Mitigation; IBPB before exit to userspace

root@turing:~# dmidecode -t baseboard
# dmidecode 3.6
Getting SMBIOS data from sysfs.
SMBIOS 3.3.0 present.

Handle 0x0002, DMI type 2, 15 bytes
Base Board Information
Manufacturer: ASUSTeK COMPUTER INC.
Product Name: ROG STRIX B550-I GAMING
Version: Rev X.0x
Serial Number: XXXX
Asset Tag: Default string
Features:
Board is a hosting board
Board is replaceable
Location In Chassis: Default string
Chassis Handle: 0x0003
Type: Motherboard
Contained Object Handles: 0

Handle 0x001E, DMI type 10, 6 bytes
On Board Device Information
Type: Video
Status: Enabled
Description: To Be Filled By O.E.M.

Handle 0x0024, DMI type 41, 11 bytes
Onboard Device
Reference Designation: Onboard IGD
Type: Video
Status: Enabled
Type Instance: 1
Bus Address: 0000:00:02.0

root@turing:~# zpool status
pool: rpool
state: ONLINE
config:

NAME STATE READ WRITE CKSUM
rpool ONLINE 0 0 0
nvme-eui.00000000000000000026b728327b7ed5-part3 ONLINE 0 0 0

errors: No known data errors
root@turing:~#