CVE-2026-98627

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Preserve packet pointer class displacement in regsafe() regsafe() maps packet pointer IDs between states and checks that each current register range is a subset of the corresponding explored register range. It does not, however, preserve the displacement between registers that share a packet pointer ID. This is unsound because packet range is shared by ID. A bounds check on one class member updates every member, and a later access can consume the range through another member. Commit 022ac0750883 ("bpf: use reg->var_off instead of reg->off for pointers") folded the fixed pointer offset into r64 and removed the old off equality check, so two individually narrower registers can prune even when their displacement has changed. The explored path can then license an out-of-bounds packet access on the pruned path. Require matching range bases for packet pointers with an ID. Together with the existing ID mapping, this preserves the displacement between members of each packet-pointer class without adding per-ID state. Packet pointers without an ID remain unaffected.

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

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

Published

2026-10-18 16:17:15.760000

Last modified

2026-10-19 10:19:26.953000

View original CVE JSON

{
  "id": "CVE-2026-98627",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-18T16:17:15.760",
  "lastModified": "2026-10-19T10:19:26.953",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Preserve packet pointer class displacement in regsafe()\n\nregsafe() maps packet pointer IDs between states and checks that each\ncurrent register range is a subset of the corresponding explored\nregister range. It does not, however, preserve the displacement between\nregisters that share a packet pointer ID.\n\nThis is unsound because packet range is shared by ID. A bounds check on\none class member updates every member, and a later access can consume the\nrange through another member. Commit 022ac0750883 (\"bpf: use reg->var_off\ninstead of reg->off for pointers\") folded the fixed pointer offset into\nr64 and removed the old off equality check, so two individually narrower\nregisters can prune even when their displacement has changed. The\nexplored path can then license an out-of-bounds packet access on the\npruned path.\n\nRequire matching range bases for packet pointers with an ID. Together\nwith the existing ID mapping, this preserves the displacement between\nmembers of each packet-pointer class without adding per-ID state.\nPacket pointers without an ID remain unaffected."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "kernel/bpf/states.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "022ac075088366b62e130da5e1b200bc93a47191",
              "lessThan": "091b40845bd3cf96791171ca95113e9184ccb596",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "022ac075088366b62e130da5e1b200bc93a47191",
              "lessThan": "fd16449a9b3b31a8f18944c2f0e29e4e218ca2cf",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "kernel/bpf/states.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "7.1",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "7.1",
              "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/091b40845bd3cf96791171ca95113e9184ccb596",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/fd16449a9b3b31a8f18944c2f0e29e4e218ca2cf",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}