CVE-2026-64318

Technical Description

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

partitions: aix: bound the pp_count scan to the ppe array

aix_partition() reads the physical volume descriptor into a fixed-size

struct pvd and then scans its physical-partition-extent array:

int numpps = be16_to_cpu(pvd->pp_count);

...

for (i = 0; i < numpps; i += 1) {

struct ppe *p = pvd->ppe + i;

...

lp_ix = be16_to_cpu(p->lp_ix);

pvd points at a single kmalloc()'d struct pvd whose ppe[] member holds a

fixed ARRAY_SIZE(pvd->ppe) (1016) entries, but the loop runs up to the

on-disk pp_count. pp_count is an unvalidated __be16 read straight from

the descriptor, so a crafted AIX image with pp_count larger than 1016

drives the loop to read pvd->ppe[i] past the end of the allocation (up

to 65535 entries, ~2 MB out of bounds).

The partition scan runs without mounting anything, when a block device

with a crafted AIX/IBM partition table appears (an attacker-supplied

image attached with losetup -P, or a device a

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