CVE-2026-64318
Received
Received - Intake
Buffer Overflow in Linux Kernel AIX Partition Handling
Vulnerability report for CVE-2026-64318, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-07-25
Last updated on: 2026-07-25
Assigner: kernel.org
Description
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 auto-scanned by udev), via
msdos_partition() -> aix_partition().
Clamp the scan to the number of entries the ppe[] array can hold.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| ibm | aix | * |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
