CVE-2021-47467: kunit: fix reference count leak in kfree_at_end

Severity: medium (CVSS 5.3 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-05-22 · updated 2026-06-17

Description

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);

Affected products

Linux kernel: from 5.14 before 5.14.15; 5.15-rc1, 5.15-rc2, 5.15-rc3, 5.15-rc4, 5.15-rc5 — fixed in 5.14.15

How to fix

Upgrade to a fixed version: Linux kernel 5.14.15. Check the vendor advisory for mitigations.

References

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