Bug 2425077 (CVE-2023-54043)

Summary: CVE-2023-54043 kernel: iommufd: Do not add the same hwpt to the ioas->hwpt_list twice
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Version: unspecifiedKeywords: Security
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OS: Linux   
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A linked list corruption flaw was found in the Linux kernel's iommufd subsystem. During HWPT (Hardware Page Table) specific attachment, the same hwpt can be added to the ioas->hwpt_list twice due to leftover code from a previous rework. This duplicate insertion corrupts the linked list structure, potentially causing crashes or undefined behavior.
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Description OSIDB Bzimport 2025-12-24 13:06:51 UTC 
In the Linux kernel, the following vulnerability has been resolved:

iommufd: Do not add the same hwpt to the ioas->hwpt_list twice

The hwpt is added to the hwpt_list only during its creation, it is never
added again. This hunk is some missed leftover from rework. Adding it
twice will corrupt the linked list in some cases.

It effects HWPT specific attachment, which is something the test suite
cannot cover until we can create a legitimate struct device with a
non-system iommu "driver" (ie we need the bus removed from the iommu code)
Comment 1 Alexander B 2025-12-25 04:16:21 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025122422-CVE-2023-54043-16c8@gregkh/T