FKIE_CVE-2026-98042

Vulnerability from fkie_nvd - Published: 2026-09-25 11:17 - Updated: 2026-09-25 11:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Don't resurrect a scalar id dropped by collect_linked_regs() check_cond_jmp_op() copies the compared registers into env->{false,true}_reg{1,2} before collect_linked_regs() runs and copies those snapshots back into both branch states afterwards. collect_linked_regs() records at most LINKED_REGS_MAX members of a linked registers group in the jump history and calls clear_scalar_id() for every member that does not fit. The compared register is not exempt from that. As a consequence, sync_linked_regs() might adjust ranges for more registers than bpf_bt_sync_linked_regs() can propagate precision to. Collect the linked registers before the snapshots are taken instead. This might lead to some unnecessary clear_scalar_id's, but from previous testing situations with many linked registers are extremely rare.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/73a98f96811e2cb0f4210b1caa8cb322f92f2a2b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e821ff19b8ef08255ff8d8234774ed814637e9bf
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e821ff19b8ef08255ff8d8234774ed814637e9bf",
              "status": "affected",
              "version": "ec1d77cb0ee98249142dcd0376d76e7a48ba0b31",
              "versionType": "git"
            },
            {
              "lessThan": "73a98f96811e2cb0f4210b1caa8cb322f92f2a2b",
              "status": "affected",
              "version": "ec1d77cb0ee98249142dcd0376d76e7a48ba0b31",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "7.1"
            },
            {
              "lessThan": "7.1",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Don\u0027t resurrect a scalar id dropped by collect_linked_regs()\n\ncheck_cond_jmp_op() copies the compared registers into\nenv-\u003e{false,true}_reg{1,2} before collect_linked_regs() runs and copies\nthose snapshots back into both branch states afterwards.\n\ncollect_linked_regs() records at most LINKED_REGS_MAX members of a\nlinked registers group in the jump history and calls clear_scalar_id()\nfor every member that does not fit. The compared register is not exempt\nfrom that.\n\nAs a consequence, sync_linked_regs() might adjust ranges for more\nregisters than bpf_bt_sync_linked_regs() can propagate precision to.\n\nCollect the linked registers before the snapshots are taken instead.\nThis might lead to some unnecessary clear_scalar_id\u0027s, but from\nprevious testing situations with many linked registers are\nextremely rare."
    }
  ],
  "id": "CVE-2026-98042",
  "lastModified": "2026-09-25T11:17:32.987",
  "metrics": {},
  "published": "2026-09-25T11:17:32.987",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/73a98f96811e2cb0f4210b1caa8cb322f92f2a2b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e821ff19b8ef08255ff8d8234774ed814637e9bf"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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