Skip to content
Fencer Vulns
no cvss —

CVE-2023-54232 json

m68k: Only force 030 bus error if PC not in exception table

published 2025-12-30 10 mo ago modified 2026-10-28 11 d ago also EUVD-2023-60409

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

m68k: Only force 030 bus error if PC not in exception table

__get_kernel_nofault() does copy data in supervisor mode when forcing a task backtrace log through /proc/sysrq_trigger. This is expected cause a bus error exception on e.g. NULL pointer dereferencing when logging a kernel task has no workqueue associated. This bus error ought to be ignored.

Our 030 bus error handler is ill equipped to deal with this:

Whenever ssw indicates a kernel mode access on a data fault, we don't even attempt to handle the fault and instead always send a SEGV signal (or panic). As a result, the check for exception handling at the fault PC (buried in send_sig_fault() which gets called from do_page_fault() eventually) is never used.

In contrast, both 040 and 060 access error handlers do not care whether a fault happened on supervisor mode access, and will call do_page_fault() on those, ultimately honoring the exception table.

Add a check in bus_error030 to call do_page_fault() in case we do have an entry for the fault PC in our exception table.

I had attempted a fix for this earlier in 2019 that did rely on testing pagefault_disabled() (see link below) to achieve the same thing, but this patch should be more generic.

Tested on 030 Atari Falcon.

Patch / fix

  • Linux Linux 4.14.312, 4.19.280, 5.4.240, 5.10.177, 5.15.105, 6.1.22, 6.2.9, 6.3
  • linux Debian 14, Debian 13, Debian 12 6.1.25-1

debian advisories DEBIAN-CVE-2023-54232

  • linux Ubuntu 20.04 LTS 5.4.0-156.173
  • linux Ubuntu 22.04 LTS 5.15.0-79.86
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1107.115
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1042.47
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1110.119
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1039.47
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1039.44
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1054.59

ubuntu advisories UBUNTU-CVE-2023-54232

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2023-54232 updated

kernel: m68k: Only force 030 bus error if PC not in exception table

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.