---
id: CVE-2026-64318
title: |-
  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…
summary: |-
  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…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'
published: '2026-07-25'
updated: '2026-07-27'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-64318'
references:
  - url: 'https://git.kernel.org/stable/c/09861651617ba0fec089e8b9477439e68398c110'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/2dc0bfd2fe355fb930de63c2f2eb8ced8570c579'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/44f37ee92fdcd377c41bdf6a31cdd8cc7d4c410e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4671bb74bba05fdd4acf670a35758c29e8c97b83'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/5eacdb1967378f5e5591cd27a2d8cdee2df1a599'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b5e9c09309e18fd9839ad007c238120353ca0cc4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/ce93228e2193a17d2c58b656e439bb39fe5c3af8'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fd94a779020f2ecc8b2607f4c20b34acb1763b9a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00164
epssPercentile: 0.04954
ingestedAt: '2026-07-27T06:16:50.453Z'
---

## Overview

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 auto-scanned by udev), via
msdos_partition() -> aix_partition().

Clamp the scan to the number of entries the ppe[] array can hold.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.