CVE-2026-98177

Full vulnerability record from the local CVENow database.

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)

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-06 09:17:59.787000

Last modified

2026-10-19 10:18:18.070000

View original CVE JSON

{
  "id": "CVE-2026-98177",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-06T09:17:59.787",
  "lastModified": "2026-10-19T10:18:18.070",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdkfd: Avoid integer underflow in EOP ring size calculation.\n\nThe low 6 bits of cp_hqd_eop_control store the base-2 logarithm\nof the EOP ring size. This was calculated as\n\norder_base_2(q->eop_ring_buffer_size / 4) - 1\n\nBut order_base_2 can in theory return 0, so this could underflow\n(although in practice the ring buffer size cannot be less than 4096).\n\nChange this to\n\norder_base_2(q->eop_ring_buffer_size / 8)\n\nusing properties of logarithms.\n\nAlso add to the above comment to make the mathematics more clear.\n\n(cherry picked from commit f0f43fcf8b2b3a924cad9444340921c96ed5f634)"
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c",
            "drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_vi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "d696d536f0a97ac779d6176107ac4e96d0a2f8b9",
              "lessThan": "287a34c4d712e0bdb67751e21316d9c8d75a528a",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "d696d536f0a97ac779d6176107ac4e96d0a2f8b9",
              "lessThan": "8ee521b8b189799e361d4233c5180ba56656d4d4",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_v9.c",
            "drivers/gpu/drm/amd/amdkfd/kfd_mqd_manager_vi.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4.3",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "4.3",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.8",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/287a34c4d712e0bdb67751e21316d9c8d75a528a",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8ee521b8b189799e361d4233c5180ba56656d4d4",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}