CVE-2026-97900

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: drm/drm_exec: fix up contended obj when num_objects is 0 drm_exec_prepare_array() silently returns success without calling drm_exec_lock_contended() when num_objects is zero. This breaks the invariant upheld by drm_exec_lock_obj(), where every entry point into the locking sequence must first attempt to lock any previously contended object before proceeding. Drivers that chain multiple drm_exec_prepare_array() calls per drm_exec_until_all_locked() iteration (e.g. amdgpu's userq signal/wait ioctls, which prepare separate read and write BO arrays) can pass an empty array for one of the two calls. If contention is hit while preparing the non-empty array, exec->contended is set and the loop retries; on retry, the empty-array call preceding it is a no-op that never clears exec->contended, so drm_exec_retry_on_contention() immediately jumps back to the top of the loop without ever reaching the call that would resolve the contention. This spins forever. Fix it by having drm_exec_prepare_array() call drm_exec_lock_contended() directly when num_objects is zero, so a pending contended object dont loop infinitely.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

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

Published

2026-09-25 11:17:16.787000

Last modified

2026-10-19 10:17:40.170000

View original CVE JSON

{
  "id": "CVE-2026-97900",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-25T11:17:16.787",
  "lastModified": "2026-10-19T10:17:40.170",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/drm_exec: fix up contended obj when num_objects is 0\n\ndrm_exec_prepare_array() silently returns success without calling\ndrm_exec_lock_contended() when num_objects is zero. This breaks the\ninvariant upheld by drm_exec_lock_obj(), where every entry point into\nthe locking sequence must first attempt to lock any previously\ncontended object before proceeding.\n\nDrivers that chain multiple drm_exec_prepare_array() calls per\ndrm_exec_until_all_locked() iteration (e.g. amdgpu's userq signal/wait\nioctls, which prepare separate read and write BO arrays) can pass an\nempty array for one of the two calls. If contention is hit while\npreparing the non-empty array, exec->contended is set and the loop\nretries; on retry, the empty-array call preceding it is a no-op that\nnever clears exec->contended, so drm_exec_retry_on_contention()\nimmediately jumps back to the top of the loop without ever reaching\nthe call that would resolve the contention. This spins forever.\n\nFix it by having drm_exec_prepare_array() call drm_exec_lock_contended()\ndirectly when num_objects is zero, so a pending contended object dont\nloop infinitely."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/gpu/drm/drm_exec.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "09593216bff15866f95c8ad406cb7fdcec1ee40a",
              "lessThan": "506cfed91e50cc8055799480a2fde5a18f63a21c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "09593216bff15866f95c8ad406cb7fdcec1ee40a",
              "lessThan": "831cd124ce99c3e61266bed30519d52f7c26abed",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "09593216bff15866f95c8ad406cb7fdcec1ee40a",
              "lessThan": "f3e74866018dab793ebee1fdf0ef34f7271d1f8c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "09593216bff15866f95c8ad406cb7fdcec1ee40a",
              "lessThan": "a565022c02f218ec9789c2baf4690792e7a48cbb",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "09593216bff15866f95c8ad406cb7fdcec1ee40a",
              "lessThan": "159720704d9d652b64390c11fb971e15b0a78d23",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/gpu/drm/drm_exec.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.6",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.6",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.158",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.111",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.53",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.7",
              "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/159720704d9d652b64390c11fb971e15b0a78d23",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/506cfed91e50cc8055799480a2fde5a18f63a21c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/831cd124ce99c3e61266bed30519d52f7c26abed",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a565022c02f218ec9789c2baf4690792e7a48cbb",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f3e74866018dab793ebee1fdf0ef34f7271d1f8c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}