CVE-2026-98599

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject non-negative offsets in stack_slot_obj_get_spi() bpf_get_spi() computes (-off - 1) / BPF_REG_SIZE using C division, which truncates toward zero. For off == 0, this produces spi 0, the same index used by the valid stack slot at fp-8. stack_slot_obj_get_spi() currently checks alignment and the resulting spi bounds, but does not reject the non-negative offset itself. It can therefore validate a PTR_TO_STACK register holding fp+0 against an iterator stored at fp-8 even though the runtime receives the actual fp+0 pointer. An effectful iterator kfunc can then interpret memory outside the BPF stack as iterator state. Reject non-negative offsets before converting the offset to an spi. All valid stack objects begin at a negative offset from the frame pointer.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

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

Published

2026-10-18 16:17:12.603000

Last modified

2026-10-19 10:19:21.383000

View original CVE JSON

{
  "id": "CVE-2026-98599",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-18T16:17:12.603",
  "lastModified": "2026-10-19T10:19:21.383",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject non-negative offsets in stack_slot_obj_get_spi()\n\nbpf_get_spi() computes (-off - 1) / BPF_REG_SIZE using C division,\nwhich truncates toward zero. For off == 0, this produces spi 0, the\nsame index used by the valid stack slot at fp-8.\n\nstack_slot_obj_get_spi() currently checks alignment and the resulting\nspi bounds, but does not reject the non-negative offset itself. It can\ntherefore validate a PTR_TO_STACK register holding fp+0 against an\niterator stored at fp-8 even though the runtime receives the actual fp+0\npointer. An effectful iterator kfunc can then interpret memory outside\nthe BPF stack as iterator state.\n\nReject non-negative offsets before converting the offset to an spi. All\nvalid stack objects begin at a negative offset from the frame pointer."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "06accc8779c1d558a5b5a21f2ac82b0c95827ddd",
              "lessThan": "89a7241fc7ecc1b5e47c3f071081e314523b8d9d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "06accc8779c1d558a5b5a21f2ac82b0c95827ddd",
              "lessThan": "79a9172f3ab4ad8392c5e5c8944b9b7710ade620",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.4",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.4",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.9",
              "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/79a9172f3ab4ad8392c5e5c8944b9b7710ade620",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/89a7241fc7ecc1b5e47c3f071081e314523b8d9d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}