Hi, It is my first time writing to this mailing list. If there's anything that I did wrong etiquette-wise, I hope for your forgiveness.
I have been using Debian Testing without much problem (as in rare breaks from time to time). But today, an error occurred that prevent the system from booting. Systemd still ran, but the systemd-modules service did not finish starting. I hard-resetted the laptop and changed to an older kernel. After some searching around, I tried to recreate the problem unsuccessfully. System Context: - Hardware: Dell Latitude E5470 (Skylake architecture). I don't think I have parallel port (the parallel port only comes with docking station which I do not own). - Kernel: 6.17.13+deb14-amd64 (Debian 6.17.13-1). - Bug frequency: Intermittent. It happened ONCE on this kernel, but I can not recreate it on subsequent reboots. Am I supposed to ignore this as a one-time freak accident? Or is there something dangerous here that I should care about? Here's the excerpt of what I think is important from the journalctl command. --- BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page Oops: Oops: 0010 [#1] SMP PTI CPU: 2 UID: 0 PID: 343 Comm: systemd-modules Not tainted 6.17.13+deb14-amd64 #1 PREEMPT(lazy) Debian 6.17.13-1 Hardware name: Dell Inc. Latitude E5470/0VHKV0, BIOS 1.34.3 11/20/2022 RIP: 0010:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0000:ffffd0998064fa40 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff8bde160a0800 RCX: 0000000000000007 RDX: ffffffffc116fac0 RSI: ffff8bde28714ca0 RDI: ffff8bde09b76800 RBP: ffffd0998064fa98 R08: 00000000fffffff3 R09: 0000000000000000 R10: ffff8bde1946c000 R11: fffff78544651a00 R12: ffff8bde160a0840 R13: ffff8bde09b76850 R14: ffff8bde09b76800 R15: ffff8bde10767f68 FS: 00007fd7004d6c80(0000) GS:ffff8be184308000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001353fe006 CR4: 00000000003706f0 Call Trace: <TASK> parport_register_dev_model+0x26c/0x340 [parport] lp_register+0x86/0x1b0 [lp] ? __pfx_lp_preempt+0x10/0x10 [lp] ? __pfx_port_check+0x10/0x10 [parport] lp_attach+0x89/0x110 [lp] port_check+0x24/0x30 [parport] bus_for_each_dev+0x82/0xd0 __parport_register_driver+0x82/0xb0 [parport] lp_init_module+0x39f/0xff0 [lp] ? __pfx_lp_init_module+0x10/0x10 [lp] do_one_initcall+0x58/0x300 do_init_module+0x62/0x250 ? init_module_from_file+0x8a/0xe0 init_module_from_file+0x8a/0xe0 idempotent_init_module+0x114/0x310 __x64_sys_finit_module+0x6d/0xd0 do_syscall_64+0x82/0x320 ? restore_fpregs_from_fpstate+0x46/0xa0 ? switch_fpu_return+0x5b/0xe0 ? do_syscall_64+0x200/0x320 ? __x64_sys_openat+0x61/0xa0 ? do_syscall_64+0xbb/0x320 ? count_memcg_events+0xd6/0x220 ? handle_mm_fault+0x1d6/0x2d0 ? do_user_addr_fault+0x21a/0x690 ? exc_page_fault+0x74/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fd700311aa9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 37 13 10 00 f7 d8 64 8> RSP: 002b:00007ffe8f710d98 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 RAX: ffffffffffffffda RBX: 000055db35eb5570 RCX: 00007fd700311aa9 RDX: 0000000000000004 RSI: 00007fd7004b144d RDI: 0000000000000009 RBP: 0000000000000004 R08: 0000000000000000 R09: 000055db35eb73c0 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd7004b144d R13: 0000000000020000 R14: 000055db35eb5690 R15: 0000000000000000 </TASK> Modules linked in: lp(+) parport_pc(+) nvme_fabrics parport i2c_dev configfs efi_pstore nfnetlink efivarfs autofs4 ext4 crc16 mbcache jbd2 crc32c_cryptoapi hid_logitech_hidpp hid_logitech_dj h> CR2: 0000000000000000 ---[ end trace 0000000000000000 ]--- RIP: 0010:0x0 Code: Unable to access opcode bytes at 0xffffffffffffffd6. RSP: 0000:ffffd0998064fa40 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff8bde160a0800 RCX: 0000000000000007 RDX: ffffffffc116fac0 RSI: ffff8bde28714ca0 RDI: ffff8bde09b76800 RBP: ffffd0998064fa98 R08: 00000000fffffff3 R09: 0000000000000000 R10: ffff8bde1946c000 R11: fffff78544651a00 R12: ffff8bde160a0840 R13: ffff8bde09b76850 R14: ffff8bde09b76800 R15: ffff8bde10767f68 FS: 00007fd7004d6c80(0000) GS:ffff8be184308000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 00000001353fe006 CR4: 00000000003706f0 --- Regards, Nguyễn Trần Phước Thành
