CVE-2026-64558: s390/pkey: Check length in pkey_pckmo handler implementation

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-07-29 · updated 2026-10-19
Weakness: CWE-122

Description

In the Linux kernel, the following vulnerability has been resolved: s390/pkey: Check length in pkey_pckmo handler implementation Explicitly check the length of the target buffer in the pkey_pckmo implementation of the key_to_protkey() handler function. The handler function fails, if the generated output data exceeds the length of the provided target buffer.

Affected products

Linux kernel: 6.12 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.

References

https://git.kernel.org/stable/c/02028a24e26d85262ab9c8fc4344e1f3503007fc
https://git.kernel.org/stable/c/1ac287e2af9a9112fe271427ef45eceb26bce8b4
https://git.kernel.org/stable/c/433e5e70cdc1edf382d28d08a885b22e2b98b7da
https://git.kernel.org/stable/c/614aa0491c7a190556c2345dddee0b6f5ed90989

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