Hi,

I have recently purchased a new UHD optical disc which is proving so difficult to read that both the 6.8.10 and 6.8.11 kernels throw NPE errors:

With vanilla 6.8.11: [ 173.866492] BUG: kernel NULL pointer dereference, address: 0000000000000048 [ 173.872158] #PF: supervisor read access in kernel mode [ 173.875995] #PF: error_code(0x0000) - not-present page [ 173.879836] PGD 0 P4D 0 [ 173.881075] Oops: 0000 [#1] PREEMPT SMP PTI [ 173.883960] CPU: 0 PID: 4183 Comm: umount Tainted: G I E 6.8.10 #2 [ 173.890052] Hardware name: Gigabyte Technology Co., Ltd. EX58-UD3R/EX58-UD3R, BIOS FB 05/04/2009 [ 173.897619] RIP: 0010:blk_try_enter_queue+0xc/0x75 [ 173.901120] Code: 41 00 eb 04 65 48 ff 08 58 e9 05 90 d6 ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 89 f5 53 48 89 fb e8 04 54 d6 ff <48> 8b 43 48 a8 03 74 0f f6 43 48 02 75 4d 48 8b 53 50 48 8b 02 eb [ 173.918568] RSP: 0018:ffffc90002e87b60 EFLAGS: 00010202 [ 173.922493] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 [ 173.928324] RDX: ffff88810c434740 RSI: 0000000000000000 RDI: 0000000000000000 [ 173.934156] RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000001b58 [ 173.939991] R10: 0000000000000020 R11: 0000000000000223 R12: 0000000000000000 [ 173.945824] R13: 0000000000000000 R14: ffffc90002e87d20 R15: 0000000000001b58 [ 173.951656] FS: 00007fc145466800(0000) GS:ffff888343c00000(0000) knlGS:0000000000000000 [ 173.958442] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 173.962887] CR2: 0000000000000048 CR3: 00000001413be000 CR4: 00000000000006f0 [ 173.968720] Call Trace: [ 173.969867] <TASK> [ 173.970671] ? __die_body+0x1a/0x5c [ 173.972862] ? page_fault_oops+0x321/0x36e [ 173.975664] ? exc_page_fault+0x105/0x117 [ 173.978374] ? asm_exc_page_fault+0x22/0x30 [ 173.981263] ? blk_try_enter_queue+0xc/0x75 [ 173.984147] blk_queue_enter+0x37/0x10b [ 173.986688] blk_mq_alloc_request+0x154/0x1b7 [ 173.989750] scsi_alloc_request+0xa/0x57 [scsi_mod] [ 173.993351] scsi_execute_cmd+0x5d/0x174 [scsi_mod] [ 173.996948] sr_do_ioctl+0x8d/0x1ac [sr_mod] [ 173.999930] sr_packet+0x39/0x42 [sr_mod] [ 174.002653] cdrom_get_disc_info+0x60/0xc9 [cdrom] [ 174.006156] cdrom_mrw_exit+0x25/0xe6 [cdrom] [ 174.009220] ? xa_destroy+0x7e/0xb8 [ 174.011413] ? preempt_latency_start+0x2b/0x46 [ 174.014560] sr_free_disk+0x40/0x56 [sr_mod] [ 174.017542] disk_release+0xb6/0xc4 [ 174.019735] device_release+0x5a/0x80 [ 174.022098] kobject_put+0x84/0xa4 [ 174.024204] bdev_release+0x153/0x165 [ 174.026573] deactivate_locked_super+0x2f/0x68 [ 174.029726] cleanup_mnt+0xab/0xd3 [ 174.031832] task_work_run+0x6b/0x80 [ 174.034110] resume_user_mode_work+0x22/0x55 [ 174.037082] syscall_exit_to_user_mode+0x5d/0x7b [ 174.040404] do_syscall_64+0x86/0xdc [ 174.042681] entry_SYSCALL_64_after_hwframe+0x60/0x68 [ 174.046434] RIP: 0033:0x7fc14568715b [ 174.048739] Code: c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa 31 f6 e9 05 00 00 00 0f 1f 44 00 00 f3 0f 1e fa b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 89 9c 0c 00 f7 d8 [ 174.066185] RSP: 002b:00007ffddee09a88 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 174.072450] RAX: 0000000000000000 RBX: 000055607dd37e60 RCX: 00007fc14568715b [ 174.078283] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055607dd38270 [ 174.084117] RBP: 00007ffddee09b60 R08: 000055607dd3a350 R09: 00007fc145751b20 [ 174.089947] R10: 0000000000000008 R11: 0000000000000246 R12: 000055607dd37f68 [ 174.095773] R13: 0000000000000000 R14: 000055607dd38270 R15: 000055607dd393d0 [ 174.101608] </TASK> [ 174.102500] Modules linked in: udf snd_seq_dummy rpcrdma rdma_cm iw_cm ib_cm ib_core nf_nat_ftp nf_conntrack_ftp cfg80211 af_packet nf_conntrack_netbios_ns nf_conntrack_broadcast nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_tables ebtable_nat ebtable_broute ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c iptable_mangle iptable_raw iptable_security ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables it87 hwmon_vid bnep binfmt_misc snd_hda_codec_realtek snd_hda_codec_hdmi snd_hda_codec_generic snd_hda_intel uvcvideo intel_powerclamp coretemp snd_intel_dspcfg btusb kvm_intel uvc videobuf2_vmalloc videobuf2_memops btintel snd_hda_codec snd_usb_audio btbcm videobuf2_v4l2 kvm bluetooth snd_virtuoso snd_hda_core videodev snd_usbmidi_lib snd_oxygen_lib snd_mpu401_uart snd_hwdep usb_storage snd_seq videobuf2_common snd_rawmidi [ 174.102617] input_leds ecdh_generic mc joydev snd_seq_device led_class rfkill snd_pcm ecc iTCO_wdt r8169 gpio_ich irqbypass pktcdvd snd_hrtimer realtek intel_cstate snd_timer intel_uncore mdio_devres psmouse libphy snd i2c_i801 mxm_wmi acpi_cpufreq i2c_smbus tiny_power_button pcspkr lpc_ich soundcore i7core_edac button nfsd(E) auth_rpcgss nfs_acl lockd grace sunrpc fuse dm_mod loop configfs dax nfnetlink zram zsmalloc amdgpu ext4 crc32c_generic crc16 mbcache jbd2 video amdxcp i2c_algo_bit mfd_core drm_ttm_helper ttm drm_exec gpu_sched sr_mod drm_suballoc_helper drm_buddy drm_display_helper cdrom sd_mod hid_microsoft usbhid drm_kms_helper ahci libahci pata_jmicron drm uhci_hcd xhci_pci libata ehci_pci ehci_hcd xhci_hcd scsi_mod usbcore firewire_ohci crc32c_intel sha512_ssse3 firewire_core sha256_ssse3 drm_panel_orientation_quirks cec sha1_ssse3 serio_raw bsg rc_core crc_itu_t usb_common scsi_common wmi msr [ 174.269914] CR2: 0000000000000048 [ 174.271981] ---[ end trace 0000000000000000 ]--- [ 174.275308] RIP: 0010:blk_try_enter_queue+0xc/0x75 [ 174.278892] Code: 41 00 eb 04 65 48 ff 08 58 e9 05 90 d6 ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 89 f5 53 48 89 fb e8 04 54 d6 ff <48> 8b 43 48 a8 03 74 0f f6 43 48 02 75 4d 48 8b 53 50 48 8b 02 eb [ 174.296345] RSP: 0018:ffffc90002e87b60 EFLAGS: 00010202 [ 174.300320] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 [ 174.306156] RDX: ffff88810c434740 RSI: 0000000000000000 RDI: 0000000000000000 [ 174.312035] RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000001b58 [ 174.317946] R10: 0000000000000020 R11: 0000000000000223 R12: 0000000000000000 [ 174.323860] R13: 0000000000000000 R14: ffffc90002e87d20 R15: 0000000000001b58 [ 174.329743] FS: 00007fc145466800(0000) GS:ffff888343c00000(0000) knlGS:0000000000000000 [ 174.336601] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 174.341136] CR2: 0000000000000048 CR3: 00000001413be000 CR4: 00000000000006f0

And with vanilla 6.8.10: [ 4426.333116] BUG: kernel NULL pointer dereference, address: 0000000000000048 [ 4426.338778] #PF: supervisor read access in kernel mode [ 4426.342617] #PF: error_code(0x0000) - not-present page [ 4426.346455] PGD 0 P4D 0 [ 4426.347696] Oops: 0000 [#1] PREEMPT SMP PTI [ 4426.350581] CPU: 4 PID: 9349 Comm: umount Tainted: G I 6.8.11 #1 [ 4426.356674] Hardware name: Gigabyte Technology Co., Ltd. EX58-UD3R/EX58-UD3R, BIOS FB 05/04/2009 [ 4426.364242] RIP: 0010:blk_try_enter_queue+0xc/0x75 [ 4426.367744] Code: 41 00 eb 04 65 48 ff 08 58 e9 05 90 d6 ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 89 f5 53 48 89 fb e8 04 54 d6 ff <48> 8b 43 48 a8 03 74 0f f6 43 48 02 75 4d 48 8b 53 50 48 8b 02 eb [ 4426.385189] RSP: 0018:ffffc9000186bb60 EFLAGS: 00010202 [ 4426.389114] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 [ 4426.394946] RDX: ffff8881852b3900 RSI: 0000000000000000 RDI: 0000000000000000 [ 4426.400780] RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000001b58 [ 4426.406611] R10: 0000000000000020 R11: 0000000000000235 R12: 0000000000000000 [ 4426.412445] R13: 0000000000000000 R14: ffffc9000186bd20 R15: 0000000000001b58 [ 4426.418279] FS: 00007f2d5041e800(0000) GS:ffff888343d00000(0000) knlGS:0000000000000000 [ 4426.425063] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4426.429510] CR2: 0000000000000048 CR3: 000000021d394000 CR4: 00000000000006f0 [ 4426.435350] Call Trace: [ 4426.436505] <TASK> [ 4426.437311] ? __die_body+0x1a/0x5c [ 4426.439511] ? page_fault_oops+0x321/0x36e [ 4426.442320] ? exc_page_fault+0x105/0x117 [ 4426.445031] ? asm_exc_page_fault+0x22/0x30 [ 4426.447924] ? blk_try_enter_queue+0xc/0x75 [ 4426.450812] blk_queue_enter+0x37/0x10b [ 4426.453354] blk_mq_alloc_request+0x154/0x1b7 [ 4426.456421] scsi_alloc_request+0xa/0x57 [scsi_mod] [ 4426.460026] scsi_execute_cmd+0x5d/0x174 [scsi_mod] [ 4426.463633] sr_do_ioctl+0x8d/0x1ac [sr_mod] [ 4426.466613] sr_packet+0x39/0x42 [sr_mod] [ 4426.469335] cdrom_get_disc_info+0x60/0xc9 [cdrom] [ 4426.472837] cdrom_mrw_exit+0x25/0xe6 [cdrom] [ 4426.475904] ? xa_destroy+0x7e/0xb8 [ 4426.478104] ? preempt_latency_start+0x2b/0x46 [ 4426.481251] sr_free_disk+0x40/0x56 [sr_mod] [ 4426.484232] disk_release+0xb6/0xc4 [ 4426.486424] device_release+0x5a/0x80 [ 4426.488790] kobject_put+0x84/0xa4 [ 4426.490895] bdev_release+0x153/0x165 [ 4426.493263] deactivate_locked_super+0x2f/0x68 [ 4426.496408] cleanup_mnt+0xab/0xd3 [ 4426.498514] task_work_run+0x6b/0x80 [ 4426.500811] resume_user_mode_work+0x22/0x55 [ 4426.503784] syscall_exit_to_user_mode+0x5d/0x7b [ 4426.507102] do_syscall_64+0x86/0xdc [ 4426.509383] entry_SYSCALL_64_after_hwframe+0x60/0x68 [ 4426.513143] RIP: 0033:0x7f2d5063f15b [ 4426.515456] Code: c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 f3 0f 1e fa 31 f6 e9 05 00 00 00 0f 1f 44 00 00 f3 0f 1e fa b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 8b 15 89 9c 0c 00 f7 d8 [ 4426.532903] RSP: 002b:00007fff2878dcb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 [ 4426.539167] RAX: 0000000000000000 RBX: 000055cd5ee85e60 RCX: 00007f2d5063f15b [ 4426.545002] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055cd5ee86270 [ 4426.550891] RBP: 00007fff2878dd90 R08: 000055cd5ee88350 R09: 00007f2d50709b20 [ 4426.556719] R10: 0000000000000008 R11: 0000000000000246 R12: 000055cd5ee85f68 [ 4426.562550] R13: 0000000000000000 R14: 000055cd5ee86270 R15: 000055cd5ee873d0 [ 4426.568386] </TASK> [ 4426.569277] Modules linked in: sg udf usb_storage uinput snd_seq_dummy rpcrdma rdma_cm iw_cm ib_cm ib_core nf_nat_ftp nf_conntrack_ftp cfg80211 af_packet nf_conntrack_netbios_ns nf_conntrack_broadcast nft_fib_inet nft_fib_ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_tables ebtable_nat ebtable_broute ip6table_nat ip6table_mangle ip6table_raw ip6table_security iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c iptable_mangle iptable_raw iptable_security ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter ip_tables x_tables it87 hwmon_vid bnep rc_pinnacle_pctv_hd em28xx_rc binfmt_misc tda18271 snd_hda_codec_realtek snd_hda_codec_hdmi cxd2820r snd_hda_codec_generic snd_hda_intel regmap_i2c em28xx_dvb dvb_core uvcvideo btusb btintel uvc intel_powerclamp videobuf2_vmalloc coretemp btbcm snd_usb_audio videobuf2_memops em28xx kvm_intel videobuf2_v4l2 bluetooth tveeprom snd_intel_dspcfg videodev snd_hda_codec snd_virtuoso kvm [ 4426.569392] videobuf2_common [ 4426.583929] usb 2-4: new high-speed USB device number 6 using ehci-pci [ 4426.657557] snd_oxygen_lib snd_usbmidi_lib snd_hda_core snd_mpu401_uart snd_hwdep snd_rawmidi mc snd_seq input_leds led_class joydev ecdh_generic rfkill snd_seq_device ecc iTCO_wdt gpio_ich r8169 snd_pcm irqbypass snd_hrtimer pktcdvd realtek snd_timer intel_cstate mdio_devres snd libphy psmouse intel_uncore i2c_i801 pcspkr acpi_cpufreq i2c_smbus mxm_wmi soundcore lpc_ich i7core_edac tiny_power_button button nfsd auth_rpcgss nfs_acl lockd grace dm_mod sunrpc fuse loop configfs dax nfnetlink zram zsmalloc amdgpu ext4 crc32c_generic crc16 mbcache jbd2 video amdxcp i2c_algo_bit mfd_core drm_ttm_helper ttm drm_exec gpu_sched drm_suballoc_helper drm_buddy drm_display_helper drm_kms_helper sr_mod hid_microsoft sd_mod cdrom usbhid drm xhci_pci uhci_hcd ehci_pci ahci ehci_hcd pata_jmicron libahci xhci_hcd libata drm_panel_orientation_quirks cec usbcore crc32c_intel scsi_mod sha512_ssse3 rc_core firewire_ohci firewire_core bsg serio_raw sha256_ssse3 sha1_ssse3 usb_common crc_itu_t scsi_common wmi msr [ 4426.750898] CR2: 0000000000000048 [ 4426.752950] ---[ end trace 0000000000000000 ]--- [ 4426.756276] RIP: 0010:blk_try_enter_queue+0xc/0x75 [ 4426.759776] Code: 41 00 eb 04 65 48 ff 08 58 e9 05 90 d6 ff 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 89 f5 53 48 89 fb e8 04 54 d6 ff <48> 8b 43 48 a8 03 74 0f f6 43 48 02 75 4d 48 8b 53 50 48 8b 02 eb [ 4426.777232] RSP: 0018:ffffc9000186bb60 EFLAGS: 00010202 [ 4426.781165] RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 [ 4426.786998] RDX: ffff8881852b3900 RSI: 0000000000000000 RDI: 0000000000000000 [ 4426.790807] usb-storage 2-4:1.0: USB Mass Storage device detected [ 4426.792867] RBP: 0000000000000000 R08: 0000000000000002 R09: 0000000000001b58 [ 4426.797877] scsi host10: usb-storage 2-4:1.0 [ 4426.803501] R10: 0000000000000020 R11: 0000000000000235 R12: 0000000000000000 [ 4426.812322] R13: 0000000000000000 R14: ffffc9000186bd20 R15: 0000000000001b58 [ 4426.818165] FS: 00007f2d5041e800(0000) GS:ffff888343d00000(0000) knlGS:0000000000000000 [ 4426.824958] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 4426.829402] CR2: 0000000000000048 CR3: 000000021d394000 CR4: 00000000000006f0 [ 4427.835567] scsi 10:0:0:0: CD-ROM HL-DT-ST BD-RE BU40N 1.00 PQ: 0 ANSI: 0

Cheers, Chris