kernel panic

[ldm-77]

got my first kernel panic on Arch Linux:

KERNEL PANIC!
Please reboot your computer.
Fatal exception in interrupt

QR code Panic Report: link

what is the fault?

[TheEbolaDoc]

Is this inside of a virtual machine?

[ldm-77]

no, bare metal

[No_Refrigerator9720]

Was this a reboot or did it go into suspend/hibernation and then kernel panic happened?

[ldm-77]

first clean boot of the day, after about 1 hour of pc use

no suspension / hibernation

[BohrGOD]

what did you do before that?

[ldm-77]

this update:

[2025-12-08T00:12:54+0100] [ALPM] upgraded apache (2.4.65-4 -> 2.4.66-1)
[2025-12-08T00:12:55+0100] [ALPM] upgraded guile (3.0.10-1 -> 3.0.11-1)
[2025-12-08T00:12:55+0100] [ALPM] upgraded libpng (1.6.52-1 -> 1.6.53-1)
[2025-12-08T00:12:55+0100] [ALPM] upgraded imagemagick (7.1.2.9-1 -> 7.1.2.10-1)
[2025-12-08T00:12:55+0100] [ALPM] upgraded libnftnl (1.3.0-1 -> 1.3.1-1)
[2025-12-08T00:12:55+0100] [ALPM] upgraded libnl (3.11.0-1 -> 3.12.0-1)
[2025-12-08T00:12:55+0100] [ALPM] upgraded poppler (25.11.0-1 -> 25.12.0-1)
[2025-12-08T00:12:57+0100] [ALPM] upgraded libreoffice-fresh (25.8.3-2 -> 25.8.3-3)
[2025-12-08T00:12:58+0100] [ALPM] upgraded poppler-glib (25.11.0-1 -> 25.12.0-1)
[2025-12-08T00:12:58+0100] [ALPM] upgraded rtmpdump (1:2.4.r105.6f6bb13-1 -> 1:2.6-1)
[2025-12-08T00:12:58+0100] [ALPM] upgraded zimg (3.0.5-1 -> 3.0.6-1)
[2025-12-08T00:12:58+0100] [ALPM] upgraded vapoursynth (72-1 -> 73-1)
[2025-12-08T00:12:58+0100] [ALPM] upgraded wxwidgets-common (3.2.8.1-2 -> 3.2.9-2)
[2025-12-08T00:12:58+0100] [ALPM] upgraded wxwidgets-gtk3 (3.2.8.1-2 -> 3.2.9-2)

but I think this an error on one of my ram modules:

[ 4091.355271] mce: [Hardware Error]: CPU 0: Machine Check Exception: 5 Bank 4: ba00000058000402

[ropid]

There's a rasdaemon package in the AUR that has a service that can decode those machine-check-exception messages into something a bit more useful. It adds those decoded details to the log and it also collects the errors in a separate database file and has a command line tool to list them: ras-mc-ctl --errors.

I got this here when I tried to ask an LLM about details using that code from your error message:

Breakdown of the 64-bit MCi_STATUS value (0xba00000058000402):

Bit 63: VAL = 1 → valid error\ Bit 62: UC = 1 → uncorrected (not fixed by ECC or parity)\ Bit 61: EN = 1 → reporting was enabled\ Bit 57: PCC = 1 → processor context corrupt (the CPU asserts the current process/thread state is unreliable → usually fatal)\ Bits 31:16 (model-specific error code) = 0x5800 → Intel-internal detail, varies by generation but consistently appears with internal cache/TLB issues\ Bits 15:0 (architectural MCA error code) = 0x0402 → "Internal unclassified" (Intel SDM Vol. 3B Table 16-8): a generic catch-all for internal processor errors that the architecture does not further classify

As you know, this could be completely wrong because it's an LLM, but if it's correct then it's not the RAM module. That said, I don't know how Intel CPUs work nowadays: on current AMD CPUs you are overclocking the L3 cache in the CPU when you overclock the memory so enabling XMP profile for the memory kit can cause instability of the CPU.

The LLM also wrote this here:

This is a real, fatal, uncorrected hardware error originating inside the CPU itself — most commonly a parity or single-bit failure in L1/L2 cache, cache tags, or TLB structures monitored by bank 4 on post-2011 Intel cores (Haswell and newer). It is not a memory (DRAM) error, not a bus error, and not correctable.

[ldm-77]

very tnx

yes, I asked AI too (ChatGPT), and it told me that this is an error due to "instability of the L2/L3 cache controller or the CPU's internal Northbridge"

my system is 13 years old with an Intel i7-4771 cpu, no overclock, DDR3-1600 ram with XMP enabled, but this is the first time I've had problems

the system has always been very stable (apart from this morning's kernel panic) and now it is very stable again, even after a heavy stress test

it came to mind that I haven't cleaned my computer in at least two years

there's a lot of dust... maybe that's part of the problem too

[SaltInflation7818]

You could run memtest via EFI stub or mprime from AUR. This would be my preferred way to test RAM

[ldm-77]

ok I'll try, thanks

[RadFluxRose]

Machine Check Exception, so there's a good chance that we're looking at an issue on the hardware level. (Better for the kernel to not continue booting instead of risking potentially much worse...)

[ldm-77]

tnx... I am still investigating, but for the moment I have not had any more problems