Hi,
After installing the kernel 6.18.8 (from previous 6.18.4), I noticed that the PC left on standby would freeze after a few hours (Debian Linux with KDE Plasma). When switching sessions to access the terminal after entering the username, the password prompt didn't appear.
The system was also inaccessible via SSH, although it was pingable.
I realized a kernel bug had been detected, but I'm not sure if that's the cause of the problem.
The bug detected is the following:

[lun feb 2 18:25:38 2026] BUG: kernel NULL pointer dereference, address: 0000000000000000
[lun feb 2 18:25:38 2026] #PF: supervisor instruction fetch in kernel mode
[lun feb 2 18:25:38 2026] #PF: error_code(0x0010) - not-present page
[lun feb 2 18:25:38 2026] PGD 0 P4D 0
[lun feb 2 18:25:38 2026] Oops: Oops: 0010 [#1] SMP NOPTI
[lun feb 2 18:25:38 2026] CPU: 4 UID: 0 PID: 12185 Comm: scan-thread Not tainted 6.18.8-1-liquorix-amd64 #1 PREEMPT liquorix 6.18-9.1~sid 61cdfd129a04b9cc5e45f09ea71a6a9e675b6571
[lun feb 2 18:25:38 2026] Hardware name: ASRock Z790M-ITX WiFi/Z790M-ITX WiFi, BIOS 18.03 05/02/2025
[lun feb 2 18:25:38 2026] RIP: 0010:0x0
[lun feb 2 18:25:38 2026] Code: Unable to access opcode bytes at 0xffffffffffffffd6.
[lun feb 2 18:25:38 2026] RSP: 0018:ffffc9000ab2bba8 EFLAGS: 00010086
[lun feb 2 18:25:38 2026] RAX: 0000000000000000 RBX: ffff888180384c00 RCX: 0000000000000286
[lun feb 2 18:25:38 2026] RDX: 00000000000000ff RSI: ffff8881035c1880 RDI: ffff88824013b800
[lun feb 2 18:25:38 2026] RBP: ffff88824013b800 R08: 0000000000001000 R09: ffff888105cb2000
[lun feb 2 18:25:38 2026] R10: ffffc9000ab2bc28 R11: 00000000ffffffff R12: 0000000000000000
[lun feb 2 18:25:38 2026] R13: ffff8881438b3140 R14: 0000000000000286 R15: ffffc9000ab2bda0
[lun feb 2 18:25:38 2026] FS: 00007fd83a1ff6c0(0000) GS:ffff88a08b6a3000(0000) knlGS:0000000000000000
[lun feb 2 18:25:38 2026] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[lun feb 2 18:25:38 2026] CR2: ffffffffffffffd6 CR3: 000000020606f001 CR4: 0000000000f72ef0
[lun feb 2 18:25:38 2026] PKRU: 55555554
[lun feb 2 18:25:38 2026] Call Trace:
[lun feb 2 18:25:38 2026] <TASK>
[lun feb 2 18:25:38 2026] parport_claim+0xd0/0x230 [parport 00fe3f35f4bc56d991a2c8ad9a96a9f7b36b56ec]
[lun feb 2 18:25:38 2026] parport_claim_or_block+0x2b/0xf0 [parport 00fe3f35f4bc56d991a2c8ad9a96a9f7b36b56ec]
[lun feb 2 18:25:38 2026] ? exact_lock+0x22/0x50
[lun feb 2 18:25:38 2026] lp_open+0x1de/0x240 [lp 4138b056f4514e75cd2a462a92ade7e2a1a715da]
[lun feb 2 18:25:38 2026] chrdev_open+0xa9/0x210
[lun feb 2 18:25:38 2026] ? __pfx_chrdev_open+0x10/0x10
[lun feb 2 18:25:38 2026] do_dentry_open+0x240/0x480
[lun feb 2 18:25:38 2026] vfs_open+0x2c/0x100
[lun feb 2 18:25:38 2026] path_openat+0x330/0x1240
[lun feb 2 18:25:38 2026] do_filp_open+0xc3/0x170
[lun feb 2 18:25:38 2026] ? do_read_fault+0x1af/0x220
[lun feb 2 18:25:38 2026] ? refill_obj_stock+0x12e/0x240
[lun feb 2 18:25:38 2026] ? kmem_cache_alloc_noprof+0x3fa/0x620
[lun feb 2 18:25:38 2026] ? __check_object_size+0x1ce/0x220
[lun feb 2 18:25:38 2026] __x64_sys_openat+0xc1/0x1f0
[lun feb 2 18:25:38 2026] do_syscall_64+0x5f/0xfe0
[lun feb 2 18:25:38 2026] ? exc_page_fault+0x65/0x150
[lun feb 2 18:25:38 2026] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[lun feb 2 18:25:38 2026] RIP: 0033:0x7fd8b055e6de
[lun feb 2 18:25:38 2026] Code: 08 0f 85 15 47 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 90 48 83 ec 08 bf 01 00 00 00 e8 c2 e5 05 00 bf 01 00 00 00 89
[lun feb 2 18:25:38 2026] RSP: 002b:00007fd83a1fb408 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
[lun feb 2 18:25:38 2026] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd8b055e6de
[lun feb 2 18:25:38 2026] RDX: 0000000000000100 RSI: 00007fd83a1fb4d0 RDI: ffffffffffffff9c
[lun feb 2 18:25:38 2026] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
[lun feb 2 18:25:38 2026] R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd83a1fd4c0
[lun feb 2 18:25:38 2026] R13: 00007fd89000803d R14: 00007fd83a1fb7c4 R15: 00007fd7ec02fbd0
[lun feb 2 18:25:38 2026] </TASK>
[lun feb 2 18:25:38 2026] Modules linked in: rfcomm usblp snd_seq_dummy snd_hrtimer xe drm_gpuvm drm_gpusvm_helper gpu_sched drm_exec drm_suballoc_helper drm_ttm_helper snd_hda_codec_intelhdmi snd_hda_codec_alc662 snd_hda_codec_realtek_lib snd_hda_codec_generic qrtr cmac algif_hash algif_skcipher af_alg bnep spd5118 sunrpc nls_iso8859_1 nls_cp437 vfat fat snd_hda_intel snd_sof_pci_intel_tgl snd_sof_pci_intel_cnl snd_sof_intel_hda_generic soundwire_intel snd_sof_intel_hda_sdw_bpt snd_sof_intel_hda_common snd_soc_hdac_hda intel_rapl_msr snd_sof_intel_hda_mlink snd_sof_intel_hda snd_hda_codec_hdmi intel_rapl_common soundwire_cadence intel_uncore_frequency mei_hdcp mei_pxp intel_uncore_frequency_common snd_sof_pci snd_sof_xtensa_dsp snd_sof snd_sof_utils snd_soc_acpi_intel_match i915 snd_soc_acpi_intel_sdca_quirks soundwire_generic_allocation snd_soc_acpi soundwire_bus snd_soc_sdca crc8 iwlmvm snd_soc_avs snd_soc_hda_codec x86_pkg_temp_thermal drm_buddy intel_powerclamp drm_client_lib snd_hda_ext_core mac80211 ttm snd_usb_audio
[lun feb 2 18:25:38 2026] snd_hda_codec i2c_algo_bit libarc4 snd_hda_core btusb snd_ump drm_display_helper btbcm snd_intel_dspcfg kvm_intel snd_usbmidi_lib btmtk snd_intel_sdw_acpi cec btrtl snd_hwdep btintel iwlwifi spi_nor snd_rawmidi rc_core snd_soc_core mousedev kvm bluetooth mc drm_kms_helper mtd snd_compress wmi_bmof ac97_bus irqbypass cfg80211 intel_gtt snd_pcm_dmaengine agpgart intel_pmc_core pmt_telemetry pmt_discovery tpm_crb pmt_class tpm_tis intel_pmc_ssram_telemetry tpm_tis_core intel_vsec acpi_pad acpi_tad sg mei_me mei snd_aloop snd_seq nct6775 snd_pcm ecryptfs dm_crypt snd_seq_device option nct6775_core yenta_socket encrypted_keys snd_timer ee1004 hso usb_wwan at24 hwmon_vid sky2 skge coretemp pcmcia_rsrc snd trusted mptspi tun usbserial rfkill af_packet pcmcia_core joydev parport_pc lp sbs ppdev asn1_encoder soundcore mptscsih psmouse e1000 tee mptbase scsi_transport_spi serio_raw msr ata_piix sbshc parport i2c_dev ata_generic drm fuse nvme_fabrics efi_pstore nfnetlink zram tpm libaescfb ecdh_generic dmi_sysfs
[lun feb 2 18:25:38 2026] raid10 raid0 linear f2fs jfs nls_ucs2_utils nilfs2 btrfs blake2b_generic nbd xfs ext4 crc16 mbcache jbd2 loop hid_logitech_hidpp hid_logitech_dj usbhid raid1 dm_raid raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx md_mod xor raid6_pq dm_mod uas usb_storage i2c_designware_platform ccp rng_core i2c_designware_core polyval_clmulni intel_lpss_pci ghash_clmulni_intel video intel_lpss aesni_intel spi_intel_pci igc idma64 wmi e1000e spi_intel
[lun feb 2 18:25:38 2026] CR2: 0000000000000000
[lun feb 2 18:25:38 2026] ---[ end trace 0000000000000000 ]---

Thanks,
Antonio
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