Linux Kernel up to 5.14.14 kfree_at_end memory leak

Summaryinfo

A vulnerability has been found in Linux Kernel up to 5.14.14 and classified as critical. This issue affects the function kfree_at_end. Performing a manipulation results in memory leak. This vulnerability was named CVE-2021-47467. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 5.14.14. This affects the function kfree_at_end. The manipulation with an unknown input leads to a memory leak vulnerability. CWE is classifying the issue as CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. This is going to have an impact on availability. The summary by CVE is:

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 CHECK: Alignment should match open parenthesis + kunit_alloc_resource(test, NULL, kfree_res_free, GFP_KERNEL, (void *)to_free);

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2021-47467. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 5.14.15 eliminates this vulnerability. Applying the patch bbdd158b40b6/f62314b1ced2 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.14.0
• 5.14.1
• 5.14.2
• 5.14.3
• 5.14.4
• 5.14.5
• 5.14.6
• 5.14.7
• 5.14.8
• 5.14.9
• 5.14.10
• 5.14.11
• 5.14.12
• 5.14.13
• 5.14.14

License

• open-source

Website

• Vendor: https://www.kernel.org/

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