CVE-2023-54232

/// Technical description

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 c

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References