CVE-2026-89978

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: accel/amdxdna: return early from a zero-length flush SYNC_BO does not constrain its size, so a request for zero bytes reaches drm_clflush_virt_range(), which ends with an unconditional clflushopt(end - 1). For an empty range that is the byte before the mapping, and abo->mem.kva comes from vmap(), so the access lands in the guard page below the vmalloc area and faults: BUG: unable to handle page fault for address: ffffd16fbbc70fff #PF: supervisor read access in kernel mode Oops: Oops: 0000 [#1] SMP NOPTI CPU: 7 UID: 1000 Comm: sync_bo_probe RIP: 0010:drm_clflush_virt_range+0x3c/0x70 Call Trace: amdxdna_drm_sync_bo_ioctl+0x124/0x430 [amdxdna] drm_ioctl+0x301/0x4c0 __x64_sys_ioctl+0x115/0x2f0 do_syscall_64+0xa6/0x3d0 Any process that can open the render node can do this. Reproduced 3 of 3 times on a Strix Point NPU (1022:17f0), by calling SYNC_BO with size 0 on an AMDXDNA_BO_SHARE object. The import arm takes the same request but flushes the whole scatterlist, so it survives it. Nothing needs flushing for an empty range, so answer before choosing a path.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

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

Published

2026-09-16 11:17:08.667000

Last modified

2026-10-19 09:18:44.607000

View original CVE JSON

{
  "id": "CVE-2026-89978",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-16T11:17:08.667",
  "lastModified": "2026-10-19T09:18:44.607",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\naccel/amdxdna: return early from a zero-length flush\n\nSYNC_BO does not constrain its size, so a request for zero bytes reaches\ndrm_clflush_virt_range(), which ends with an unconditional\nclflushopt(end - 1). For an empty range that is the byte before the\nmapping, and abo->mem.kva comes from vmap(), so the access lands in the\nguard page below the vmalloc area and faults:\n\n  BUG: unable to handle page fault for address: ffffd16fbbc70fff\n  #PF: supervisor read access in kernel mode\n  Oops: Oops: 0000 [#1] SMP NOPTI\n  CPU: 7 UID: 1000 Comm: sync_bo_probe\n  RIP: 0010:drm_clflush_virt_range+0x3c/0x70\n  Call Trace:\n   amdxdna_drm_sync_bo_ioctl+0x124/0x430 [amdxdna]\n   drm_ioctl+0x301/0x4c0\n   __x64_sys_ioctl+0x115/0x2f0\n   do_syscall_64+0xa6/0x3d0\n\nAny process that can open the render node can do this. Reproduced 3 of 3\ntimes on a Strix Point NPU (1022:17f0), by calling SYNC_BO with size 0 on\nan AMDXDNA_BO_SHARE object. The import arm takes the same request but\nflushes the whole scatterlist, so it survives it.\n\nNothing needs flushing for an empty range, so answer before choosing a\npath."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/accel/amdxdna/amdxdna_gem.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "e252e3f3488a49267e08ea7d972ac5ba3f2f1763",
              "lessThan": "45962da5821d0a691f638ccb13842889156d8969",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "e252e3f3488a49267e08ea7d972ac5ba3f2f1763",
              "lessThan": "f00def884a831dc49eb659dac2dd09dbfd21e67f",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "e252e3f3488a49267e08ea7d972ac5ba3f2f1763",
              "lessThan": "dc14753664240cedf669623b27ae9922b0618b25",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/accel/amdxdna/amdxdna_gem.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.17",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.17",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.52",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.5",
              "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/45962da5821d0a691f638ccb13842889156d8969",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/dc14753664240cedf669623b27ae9922b0618b25",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f00def884a831dc49eb659dac2dd09dbfd21e67f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}