Linux Kernel liveupdate luo_file_unpreserve_files/luo_file_finish use after free

Summaryinfo

A vulnerability categorized as very critical has been discovered in Linux Kernel. This issue affects the function luo_file_unpreserve_files/luo_file_finish of the component liveupdate. Executing a manipulation can lead to use after free. This vulnerability appears as CVE-2026-74369. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability was found in Linux Kernel (affected version unknown). It has been declared as very critical. This vulnerability affects the function luo_file_unpreserve_files/luo_file_finish of the component liveupdate. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: liveupdate: fix u-a-f in luo_file_unpreserve_files() and luo_file_finish() In luo_file_unpreserve_files() and luo_file_finish(), reorder module_put() and xa_erase() to ensure the file handler module remains pinned while its operations are being accessed. Specifically, luo_get_id() dereferences fh->ops->get_id, so the module reference must be held until after xa_erase() (which calls luo_get_id) completes. For luo_file_finish(), this requires moving the module_put() call out of the luo_file_finish_one() helper and into the main loop of luo_file_finish() itself.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-74369 since 08/15/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 08/15/2026).

Applying the patch f7fca3db635022429382cf26e5b08b33558e375d/291dcd37c8c8f8f8e1bccc92228f44bf371762a8 is able to eliminate this problem.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

License

• open-source

Website

• Vendor: https://www.kernel.org/

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