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

netfilter: ctnetlink: remove refcounting in expectation dumpers

Same pattern as previous patch: do not keep the expectation object
alive via refcount, only store a cookie value and then use that
as the skip hint for dump resumption.

AFAICS this has the same issue as the one resolved in the conntrack
dumper, when we do
if (!refcount_inc_not_zero(&exp->use))

to increment the refcount, there is a chance that exp == last, which
causes a double-increment of the refcount and subsequent memory leak.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Thu, 11 Sep 2025 17:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: netfilter: ctnetlink: remove refcounting in expectation dumpers Same pattern as previous patch: do not keep the expectation object alive via refcount, only store a cookie value and then use that as the skip hint for dump resumption. AFAICS this has the same issue as the one resolved in the conntrack dumper, when we do if (!refcount_inc_not_zero(&exp->use)) to increment the refcount, there is a chance that exp == last, which causes a double-increment of the refcount and subsequent memory leak.
Title netfilter: ctnetlink: remove refcounting in expectation dumpers
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-09-11T16:52:32.060Z

Reserved: 2025-04-16T07:20:57.126Z

Link: CVE-2025-39764

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2025-09-11T17:15:40.653

Modified: 2025-09-11T17:15:40.653

Link: CVE-2025-39764

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.