CVE-2026-98177

A flaw was found in the Linux kernel's AMD GPU driver (amdkfd). A local user could trigger a Denial of Service (DoS) or system instability due to an integer underflow vulnerability during the calculation of the End of Pipe (EOP) ring buffer size. Under specific conditions, this improper calculation could lead to misconfigured hardware queue controls and unexpected driver behavior.

A low impact integer underflow flaw was found in the Linux kernel AMD KFD GPU compute driver (amdkfd). The driver encoded the End of Pipe (EOP) ring buffer size into the low 6 bits of the cp_hqd_eop_control register as order_base_2(eop_ring_buffer_size / 4) - 1; since order_base_2 can in theory return 0, the subtraction could underflow and misconfigure the hardware queue control register. A local user with access to the AMD KFD GPU device interface could in theory use this misconfiguration to cause GPU queue failure, driver instability, or a denial of service. In practice, the documented allocation invariant that the EOP ring buffer cannot be smaller than 4096 bytes prevents the underflow from occurring under normal kernel operation. For this reason Red Hat rates the impact of this flaw as low, although the Red Hat CVSS 3.1 score is 5.5 (AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H, moderate). Red Hat Enterprise Linux 7 is not affected because the vulnerable code is not present, and Red Hat Enterprise Linux 6 is out of support scope. For the affected Red Hat Enterprise Linux 8, 9, and 10, Red Hat In-Vehicle OS, and OpenShift Container Platform streams, the fix is deferred because the flaw is theoretical with low practical exploitability; the residual risk is limited to a local denial of service on systems using affected AMD GPUs.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.