Use After Free Affecting kernel6.12-devel package, versions <1:6.12.46-66.121.amzn2023


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.02% (5th percentile)

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  • Snyk IDSNYK-AMZN2023-KERNEL612DEVEL-13169727
  • published1 Oct 2025
  • disclosed5 Sept 2025

Introduced: 5 Sep 2025

CVE-2025-39698  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel6.12-devel to version 1:6.12.46-66.121.amzn2023 or higher.
This issue was patched in ALAS2023-2025-1208.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel6.12-devel package and not the kernel6.12-devel package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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

io_uring/futex: ensure io_futex_wait() cleans up properly on failure

The io_futex_data is allocated upfront and assigned to the io_kiocb async_data field, but the request isn't marked with REQ_F_ASYNC_DATA at that point. Those two should always go together, as the flag tells io_uring whether the field is valid or not.

Additionally, on failure cleanup, the futex handler frees the data but does not clear ->async_data. Clear the data and the flag in the error path as well.

Thanks to Trend Micro Zero Day Initiative and particularly ReDress for reporting this.

CVSS Base Scores

version 3.1