Use After Free Affecting linux-6.12 package, versions <6.12.107-1~deb12u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.46% (38th percentile)

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  • Snyk IDSNYK-ECHOLATEST-LINUX612-19964109
  • published20 Sept 2026
  • disclosed24 Jul 2026

Introduced: 24 Jul 2026

CVE-2026-64216  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Echo:latest linux-6.12 to version 6.12.107-1~deb12u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-6.12 package and not the linux-6.12 package as distributed by Echo. See How to fix? for Echo:latest relevant fixed versions and status.

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

netfs: Fix potential UAF in netfs_unlock_abandoned_read_pages()

netfs_unlock_abandoned_read_pages(rreq) accesses the index of the folios it is wanting to unlock and compares that to rreq->no_unlock_folio so that it doesn't unlock a folio being read for netfs_perform_write() or netfs_write_begin().

However, given that netfs_unlock_abandoned_read_pages() is called after NETFS_RREQ_IN_PROGRESS is cleared, the one folio that it's not allowed to dereference is the one specified by ->no_unlock_folio as ownership immediately reverts to the caller.

Fix this by storing the folio pointer instead and using that rather than the index. Also fix netfs_unlock_read_folio() where the same applies.

CVSS Base Scores

version 3.1