CVE-2022-48933: netfilter: nf_tables: fix memory leak during stateful obj update

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-08-22 · updated 2026-06-17
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: fix memory leak during stateful obj update stateful objects can be updated from the control plane. The transaction logic allocates a temporary object for this purpose. The ->init function was called for this object, so plain kfree() leaks resources. We must call ->destroy function of the object. nft_obj_destroy does this, but it also decrements the module refcount, but the update path doesn't increment it. To avoid special-casing the update object release, do module_get for the update case too and release it via nft_obj_destroy().

Affected products

Linux kernel: from 5.4 before 5.4.182; from 5.5 before 5.10.103; from 5.11 before 5.15.26; from 5.16 before 5.16.12 — fixed in 5.10.103, 5.15.26, 5.16.12, 5.4.182

How to fix

Upgrade to a fixed version: Linux kernel 5.10.103, 5.15.26, 5.16.12, 5.4.182. Check the vendor advisory for mitigations.

References

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