Linux Kernel amdkfd integer underflow

Summaryinfo

A vulnerability labeled as very critical has been found in Linux Kernel. This issue affects some unknown processing of the component amdkfd. Executing a manipulation can lead to integer underflow. This vulnerability appears as CVE-2026-98176. The attack may be performed from remote. There is no available exploit. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability was found in Linux Kernel (the affected version unknown). It has been declared as very critical. This vulnerability affects an unknown part of the component amdkfd. The manipulation with an unknown input leads to a integer underflow vulnerability. The CWE definition for the vulnerability is CWE-191. The product subtracts one value from another, such that the result is less than the minimum allowable integer value, which produces a value that is not equal to the correct result. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Avoid integer underflow with ffs in EOP ring size calc The low 6 bits of cp_hqd_eop_control store the base-2 logarithm of the EOP ring size. This was calculated as ffs(q->eop_ring_buffer_size / sizeof(unsigned int)) - 1 - 1 But ffs can in theory return 1 or 0, so this could underflow (although in practice the ring buffer size cannot be less than 4096). Change this to ffs(q->eop_ring_buffer_size / sizeof(unsigned int) / 4) using properties of logarithms. (cherry picked from commit 4f18c56630383c14bfc6b2d65f88f2f895d2121a)

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2026-98176 since 09/25/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 10/07/2026).

Applying the patch 4f18c56630383c14bfc6b2d65f88f2f895d2121a is able to eliminate this problem.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-3743). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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