CVE-2021-47467: linux kernel vulnerability

What is known

In the Linux kernel, the following vulnerability has been resolved: kunit: fix reference count leak in kfree_at_end The reference counting issue happens in the normal path of kfree_at_end(). When kunit_alloc_and_get_resource() is invoked, the function forgets to handle the returned resource object, whose refcount increased inside, causing a refcount leak. Fix this issue by calling kunit_alloc_resource() instead of kunit_alloc_and_get_resource(). Fixed the following when applying: Shuah Khan <skhan@linuxfoundation.org> CHECK: Alignment should match open parenthesis + kunit_alloc_resource(test, NULL, kfree_res_free, GFP_KERNEL, (void *)to_free);

Business impact

Successful exploitation of CVE-2021-47467, a medium vulnerability (CVSS 5.3) affecting linux kernel, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether linux kernel is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

• NVD
• Reference
• Reference