bpf: Fix REG INVARIANTS VIOLATION on speculative pointer arithmetic

{
  "id": "a1e39797df8878b2f4d258969dfc8335f32e92ea4e37b90065ebec078c49d64c",
  "url": "https://osv.dev/vulnerability/CVE-2026-98151",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "bpf: Fix REG INVARIANTS VIOLATION on speculative pointer arithmetic",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: bpf: Fix REG INVARIANTS VIOLATION on speculative pointer arithmetic Take the following unprivileged program as an example: r0 = bpf_map_lookup_elem(...) /* PTR_TO_MAP_VALUE, offset 0 */ ... 14: r0 += r1 /* r1 is a bounded scalar */ 15: r9 = r0 Loading it triggers a verifier warning from reg_bounds_sanity_check(): verifier bug: REG INVARIANTS VIOLATION (alu): const subreg tnum out of sync with range bounds r64={.base=0x0, .size=0x0} r32={.base=0x0, .size=0xffffffff} var_off=(0x0, 0x0) What happens: 1. Processing insn 14 (r0 += r1) in adjust_ptr_min_max_vals(), the new offset is computed into dst_reg's var_off and 32/64-bit ranges. 2. Because pointer registers do not track 32-bit subregister bounds, __mark_reg32_unbounded() first sets r32 to the full range; r32 is re-derived from the offset at the end of the function by reg_bounds_sync(). 3. On the unprivileged path, sanitize_ptr_alu() is called and, via sanitize_speculative_path() -> push_stack(), snapshots the current register state and schedules the next instruction (insn 15) to be verified directly as a speculative path. 4. That snapshot is taken between step 2 and the final reg_bounds_sync(): at this point dst_reg's var_off still holds the (const) original offset while r32 has just been blanked to the full range, i.e. the two are out of sync. When the speculative path later verifies insn 15 (r9 = r0), the inconsistent state reaches reg_bounds_sanity_check(",
    "evidence": "osv:CVE-2026-98151",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.111",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.53",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.7",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-98151",
      "aliases": [
        "CVE-2026-98151"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "5f99f312bd3bedb3b266b0d26376a8c500cdc97f"
                },
                {
                  "fixed": "21a681526c715aebb4f918b8c131583442d1b3d8"
                },
                {
                  "fixed": "d623a4a58bb238443505d5c2949d1182dcfc26b6"
                },
                {
                  "fixed": "9f9477ae73de9c5a28e8ab7000d8097b078faee4"
                },
                {
                  "fixed": "150aeba624e8b7cac51c39440d7e8e1fd11de9a0"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98151.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.8.0"
                },
                {
                  "fixed": "6.12.111"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.18.53"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.2.7"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98151.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:43.634026809Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/150aeba624e8b7cac51c39440d7e8e1fd11de9a0",
        "https://git.kernel.org/stable/c/21a681526c715aebb4f918b8c131583442d1b3d8",
        "https://git.kernel.org/stable/c/9f9477ae73de9c5a28e8ab7000d8097b078faee4",
        "https://git.kernel.org/stable/c/d623a4a58bb238443505d5c2949d1182dcfc26b6",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98151.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-98151",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98151.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-98151",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 511572,
  "published_at": "2026-09-25T10:36:23.412+00:00"
}