SB20260720101 - Improper Initialization in Linux kernel mm

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Initialization (CVE-ID: CVE-2026-64130)

CWE-ID: CWE-665 - Improper Initialization

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local user to disclose sensitive information.

The vulnerability exists due to improper initialization of memory tags in the huge zero folio when allocating huge zero folios with init_on_free enabled and __GFP_ZEROTAGS handling skips tag clearing. A local user can map affected memory to disclose sensitive information.

The issue affects arm64 systems using memory tagging extension, and exposure occurs because the huge zero folio is mapped through a special PMD path that does not initialize tags on first user-space mapping.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/2f2aec5120b93a8f8b52dc50cdc60dbb8aec72f6
• https://git.kernel.org/stable/c/6a288a4ddb4a994490505ab5f41c445f8e6b6467
• https://git.kernel.org/stable/c/738d18f1da3513d17b6f7bf30146cc4ac2480ffd