CVE-2025-39819 Affecting linux-6.1 package, versions <6.1.153-1~deb11u1


Severity

Recommended
low

Based on default assessment until relevant scores are available.

Threat Intelligence

EPSS
0.04% (13th percentile)

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  • Snyk IDSNYK-DEBIAN11-LINUX61-13542152
  • published14 Oct 2025
  • disclosed16 Sept 2025

Introduced: 16 Sep 2025

CVE-2025-39819  (opens in a new tab)

How to fix?

Upgrade Debian:11 linux-6.1 to version 6.1.153-1~deb11u1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-6.1 package and not the linux-6.1 package as distributed by Debian. See How to fix? for Debian:11 relevant fixed versions and status.

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

fs/smb: Fix inconsistent refcnt update

A possible inconsistent update of refcount was identified in smb2_compound_op. Such inconsistent update could lead to possible resource leaks.

Why it is a possible bug:

  1. In the comment section of the function, it clearly states that the reference to cfile should be dropped after calling this function.
  2. Every control flow path would check and drop the reference to cfile, except the patched one.
  3. Existing callers would not handle refcount update of cfile if -ENOMEM is returned.

To fix the bug, an extra goto label "out" is added, to make sure that the cleanup logic would always be respected. As the problem is caused by the allocation failure of vars, the cleanup logic between label "finished" and "out" can be safely ignored. According to the definition of function is_replayable_error, the error code of "-ENOMEM" is not recoverable. Therefore, the replay logic also gets ignored.

CVSS Base Scores

version 3.1