CVE-2026-93144 (GCVE-0-2026-93144)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:11 – Updated: 2026-09-18 17:56
VLAI
Title
bpf: Reject writes through untrusted BTF pointers
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject writes through untrusted BTF pointers check_ptr_to_btf_access() lets program-type btf_struct_access callbacks validate writes before the default BTF access path rejects non-read accesses. That bypasses the read-only policy for untrusted BTF pointers created by helpers such as bpf_rdonly_cast(). Reject non-read accesses through PTR_UNTRUSTED BTF pointers at the common entry point, before the callback branch to handle all cases.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 282de143ead96a5d53331e946f31c977b4610a74 , < 19d5566b84ca1af0256d0d0003e1a081580c3ba3 (git)
Affected: 282de143ead96a5d53331e946f31c977b4610a74 , < ac65c710cc643cbc52b899627577357867249530 (git)
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Linux Linux Affected: 6.2
Unaffected: 0 , < 6.2 (semver)
Unaffected: 7.2.6 , ≤ 7.2.* (semver)
Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "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": "19d5566b84ca1af0256d0d0003e1a081580c3ba3",
              "status": "affected",
              "version": "282de143ead96a5d53331e946f31c977b4610a74",
              "versionType": "git"
            },
            {
              "lessThan": "ac65c710cc643cbc52b899627577357867249530",
              "status": "affected",
              "version": "282de143ead96a5d53331e946f31c977b4610a74",
              "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": "6.2"
            },
            {
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "6.2",
                  "vulnerable": true
                }
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              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject writes through untrusted BTF pointers\n\ncheck_ptr_to_btf_access() lets program-type btf_struct_access callbacks\nvalidate writes before the default BTF access path rejects non-read\naccesses. That bypasses the read-only policy for untrusted BTF pointers\ncreated by helpers such as bpf_rdonly_cast().\n\nReject non-read accesses through PTR_UNTRUSTED BTF pointers at the\ncommon entry point, before the callback branch to handle all cases."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The attacker-controlled input is BPF bytecode that calls bpf_rdonly_cast() then STX, submitted via bpf(BPF_PROG_LOAD) in SYSCALL_DEFINE5(bpf) \u2192 bpf_prog_load() \u2192 bpf_check() \u2192 do_check_main() \u2192 check_mem_access() \u2192 check_ptr_to_btf_access(); no remote protocol carries that untrusted pointer or the store.\nAC:L - A BPF_PROG_TYPE_STRUCT_OPS program attached to bpf_dummy_ops (check_struct_ops_btf_id() sets env-\u003eops to bpf_dummy_ops_btf_struct_access) or a BPF_PROG_TYPE_SCHED_CLS program (tc_cls_act_btf_struct_access) does bpf_rdonly_cast() then a store; the WRITE path ran the callback before the old \"only read is supported\" check. No race.\nPR:L - check_ptr_to_btf_access() returns -EPERM unless env-\u003eallow_ptr_leaks (bpf_token_capable(CAP_PERFMON)); STRUCT_OPS also fails is_perfmon_prog_type() without CAP_PERFMON, and add_subprog_and_kfunc() needs env-\u003ebpf_capable to emit bpf_rdonly_cast. bpf_token_capable() uses ns_capable() on a delegated token userns, not init-namespace root.\nUI:N - The attacker loads that program with BPF_PROG_LOAD and runs it via BPF_PROG_TEST_RUN (bpf_struct_ops_test_run() \u2192 dummy_ops_call_op() for bpf_dummy_ops, or bpf_prog_test_run_skb() for SCHED_CLS). No other user must mount, open a file, or cooperate.\nS:U - bpf_convert_ctx_accesses() leaves PTR_TO_BTF_ID|PTR_UNTRUSTED stores as plain STX (only reads become BPF_PROBE_MEM), so the write corrupts host kernel memory in the same authority as the bpf() caller; this is not a KVM/Xen guest-to-host escape or IOMMU bypass.\nC:H - The accepted STX writes attacker bytes through a bpf_rdonly_cast() pointer (obj__ign skips type checks) at bpf_dummy_ops_state.val, nf_conn.mark, or tcp_sock.snd_cwnd. That type-confused kernel write is a memory-corruption primitive that can be turned into an arbitrary kernel read.\nI:H - bpf_dummy_ops_btf_struct_access() accepts any store within sizeof(struct bpf_dummy_ops_state), and _nf_conntrack_btf_struct_access() accepts nf_conn.mark, on a PTR_UNTRUSTED base from bpf_rdonly_cast(); the JIT emits a plain store to that address, an arbitrary kernel write usable for control-flow hijacking.\nA:H - The same unprobed STX to bpf_rdonly_cast(0, btf_id) or to an out-of-bounds map/stack address page-faults in kernel context during bpf_struct_ops_test_run()/bpf_prog_test_run_skb() and oopses/panics, and the attacker can repeat BPF_PROG_TEST_RUN at will."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-18T17:56:11.444Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/19d5566b84ca1af0256d0d0003e1a081580c3ba3"
        },
        {
          "url": "https://git.kernel.org/stable/c/ac65c710cc643cbc52b899627577357867249530"
        }
      ],
      "title": "bpf: Reject writes through untrusted BTF pointers",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-93144",
    "datePublished": "2026-09-17T16:11:42.757Z",
    "dateReserved": "2026-09-17T16:02:15.088Z",
    "dateUpdated": "2026-09-18T17:56:11.444Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-93144",
      "date": "2026-09-29",
      "epss": "0.00175",
      "percentile": "0.06279"
    },
    "microsoft_vex": {
      "current_release_date": "2026-09-23T02:49:50.000Z",
      "cve": "CVE-2026-93144",
      "id": "msrc_CVE-2026-93144",
      "initial_release_date": "2026-09-19T01:05:08.000Z",
      "product_status:known_affected": "2",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "bpf: Reject writes through untrusted BTF pointers",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-93144.json",
      "version": "2"
    },
    "nvd": {
      "cve": {
        "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": [
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                    "versionType": "git"
                  },
                  {
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              },
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                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "6.2"
                  },
                  {
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                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
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                    "status": "unaffected",
                    "version": "7.2.6",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "7.3-rc1",
                    "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: Reject writes through untrusted BTF pointers\n\ncheck_ptr_to_btf_access() lets program-type btf_struct_access callbacks\nvalidate writes before the default BTF access path rejects non-read\naccesses. That bypasses the read-only policy for untrusted BTF pointers\ncreated by helpers such as bpf_rdonly_cast().\n\nReject non-read accesses through PTR_UNTRUSTED BTF pointers at the\ncommon entry point, before the callback branch to handle all cases."
          }
        ],
        "id": "CVE-2026-93144",
        "lastModified": "2026-09-18T18:18:22.530",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 7.8,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "HIGH",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.8,
              "impactScore": 5.9,
              "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
              "type": "Secondary"
            }
          ]
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        "published": "2026-09-17T17:18:09.507",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/19d5566b84ca1af0256d0d0003e1a081580c3ba3"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/ac65c710cc643cbc52b899627577357867249530"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
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    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-09-22T16:24:07Z",
      "cve": "CVE-2026-93144",
      "id": "CVE-2026-93144",
      "initial_release_date": "2026-09-18T00:11:38Z",
      "product_status:known_affected": "108",
      "product_status:known_not_affected": "239",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-93144",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2026-93144.json",
      "version": "4"
    }
  }
}



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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.