Vulnerability-Lookup

FKIE_CVE-2026-90312

Vulnerability from fkie_nvd - Published: 2026-09-17 17:17 - Updated: 2026-09-18 18:17

Severity

7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: bpf: Check load-acquire src ptr type before the load check_atomic_load() calls check_load_mem() before atomic_ptr_type_ok(). For a load-acquire that fetches into its own source register (dst_reg == src_reg), check_load_mem() overwrites src_reg's type with the type of the loaded value, so the subsequent atomic_ptr_type_ok() no longer sees the source pointer and fails to reject the disallowed types (ctx, pkt, flow_keys, sock). Since bpf_convert_ctx_accesses() does not rewrite atomic loads, the raw access to the underlying kernel object is left in place. The destination type is taken from the ctx access itself, so a load-acquire of the sk field of struct __sk_buff for example leaves the register typed as PTR_TO_SOCK_COMMON_OR_NULL, which type_is_sk_pointer() does not match either, while it actually holds unconverted struct sk_buff bytes. Once the NULL check has passed this is a type confusion, not just a leak of kernel data. Validate src_reg with check_reg_arg() and check the source pointer type with atomic_ptr_type_ok() before the load again, mirroring check_atomic_rmw(). Out-of-range register numbers are already rejected earlier by check_and_resolve_insns() (commit 503d21ef8eac ("bpf: Do register range validation early")), and the only exemption there, is_stack_arg_ldx(), requires BPF_LDX | BPF_MEM | BPF_DW and thus never matches a BPF_ATOMIC insn. atomic_ptr_type_ok() can therefore not dereference register state out of bounds, that is, the out-of-bounds read addressed by the Fixes commit below does not reappear (as proven also via selftest).

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/422a416041172af1ac610736d5f556d22b31b115
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/6ee7b00888498cf387dd30729e18a05328b94709
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/b87803391baa7e0bef60549d8841f12e549ad057

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "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": "6ee7b00888498cf387dd30729e18a05328b94709",
              "status": "affected",
              "version": "c03bb2fa327e4c25d6c5360a8803a4b1cdc2d0b9",
              "versionType": "git"
            },
            {
              "lessThan": "422a416041172af1ac610736d5f556d22b31b115",
              "status": "affected",
              "version": "c03bb2fa327e4c25d6c5360a8803a4b1cdc2d0b9",
              "versionType": "git"
            },
            {
              "lessThan": "b87803391baa7e0bef60549d8841f12e549ad057",
              "status": "affected",
              "version": "c03bb2fa327e4c25d6c5360a8803a4b1cdc2d0b9",
              "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": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "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: Check load-acquire src ptr type before the load\n\ncheck_atomic_load() calls check_load_mem() before atomic_ptr_type_ok().\nFor a load-acquire that fetches into its own source register (dst_reg ==\nsrc_reg), check_load_mem() overwrites src_reg\u0027s type with the type of the\nloaded value, so the subsequent atomic_ptr_type_ok() no longer sees the\nsource pointer and fails to reject the disallowed types (ctx, pkt,\nflow_keys, sock).\n\nSince bpf_convert_ctx_accesses() does not rewrite atomic loads, the raw\naccess to the underlying kernel object is left in place. The destination\ntype is taken from the ctx access itself, so a load-acquire of the sk\nfield of struct __sk_buff for example leaves the register typed as\nPTR_TO_SOCK_COMMON_OR_NULL, which type_is_sk_pointer() does not match\neither, while it actually holds unconverted struct sk_buff bytes. Once\nthe NULL check has passed this is a type confusion, not just a leak of\nkernel data.\n\nValidate src_reg with check_reg_arg() and check the source pointer type\nwith atomic_ptr_type_ok() before the load again, mirroring\ncheck_atomic_rmw(). Out-of-range register numbers are already rejected\nearlier by check_and_resolve_insns() (commit 503d21ef8eac (\"bpf: Do\nregister range validation early\")), and the only exemption there,\nis_stack_arg_ldx(), requires BPF_LDX | BPF_MEM | BPF_DW and thus never\nmatches a BPF_ATOMIC insn. atomic_ptr_type_ok() can therefore not\ndereference register state out of bounds, that is, the out-of-bounds\nread addressed by the Fixes commit below does not reappear (as proven\nalso via selftest)."
    }
  ],
  "id": "CVE-2026-90312",
  "lastModified": "2026-09-18T18:17:53.130",
  "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"
      }
    ]
  },
  "published": "2026-09-17T17:17:28.977",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/422a416041172af1ac610736d5f556d22b31b115"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6ee7b00888498cf387dd30729e18a05328b94709"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b87803391baa7e0bef60549d8841f12e549ad057"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-90312 (GCVE-0-2026-90312)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:08 – Updated: 2026-09-18 17:54

Title

bpf: Check load-acquire src ptr type before the load

Summary

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/6ee7b00888498cf38…
https://git.kernel.org/stable/c/422a416041172af1a…
https://git.kernel.org/stable/c/b87803391baa7e0be…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: c03bb2fa327e4c25d6c5360a8803a4b1cdc2d0b9 , < 6ee7b00888498cf387dd30729e18a05328b94709 (git) Affected: c03bb2fa327e4c25d6c5360a8803a4b1cdc2d0b9 , < 422a416041172af1ac610736d5f556d22b31b115 (git) Affected: c03bb2fa327e4c25d6c5360a8803a4b1cdc2d0b9 , < b87803391baa7e0bef60549d8841f12e549ad057 (git)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 6.18.52 , ≤ 6.18.* (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "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": "6ee7b00888498cf387dd30729e18a05328b94709",
              "status": "affected",
              "version": "c03bb2fa327e4c25d6c5360a8803a4b1cdc2d0b9",
              "versionType": "git"
            },
            {
              "lessThan": "422a416041172af1ac610736d5f556d22b31b115",
              "status": "affected",
              "version": "c03bb2fa327e4c25d6c5360a8803a4b1cdc2d0b9",
              "versionType": "git"
            },
            {
              "lessThan": "b87803391baa7e0bef60549d8841f12e549ad057",
              "status": "affected",
              "version": "c03bb2fa327e4c25d6c5360a8803a4b1cdc2d0b9",
              "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": "6.15"
            },
            {
              "lessThan": "6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.52",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "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": "6.18.52",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc1",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Check load-acquire src ptr type before the load\n\ncheck_atomic_load() calls check_load_mem() before atomic_ptr_type_ok().\nFor a load-acquire that fetches into its own source register (dst_reg ==\nsrc_reg), check_load_mem() overwrites src_reg\u0027s type with the type of the\nloaded value, so the subsequent atomic_ptr_type_ok() no longer sees the\nsource pointer and fails to reject the disallowed types (ctx, pkt,\nflow_keys, sock).\n\nSince bpf_convert_ctx_accesses() does not rewrite atomic loads, the raw\naccess to the underlying kernel object is left in place. The destination\ntype is taken from the ctx access itself, so a load-acquire of the sk\nfield of struct __sk_buff for example leaves the register typed as\nPTR_TO_SOCK_COMMON_OR_NULL, which type_is_sk_pointer() does not match\neither, while it actually holds unconverted struct sk_buff bytes. Once\nthe NULL check has passed this is a type confusion, not just a leak of\nkernel data.\n\nValidate src_reg with check_reg_arg() and check the source pointer type\nwith atomic_ptr_type_ok() before the load again, mirroring\ncheck_atomic_rmw(). Out-of-range register numbers are already rejected\nearlier by check_and_resolve_insns() (commit 503d21ef8eac (\"bpf: Do\nregister range validation early\")), and the only exemption there,\nis_stack_arg_ldx(), requires BPF_LDX | BPF_MEM | BPF_DW and thus never\nmatches a BPF_ATOMIC insn. atomic_ptr_type_ok() can therefore not\ndereference register state out of bounds, that is, the out-of-bounds\nread addressed by the Fixes commit below does not reappear (as proven\nalso via selftest)."
        }
      ],
      "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 a BPF_LOAD_ACQ insn with dst_reg==src_reg in the bytecode bpf_prog_load() copies from bpf(2) BPF_PROG_LOAD (__sys_bpf). do_check_insn()\u2192check_atomic()\u2192check_atomic_load() then lets check_load_mem() overwrite the source type before atomic_ptr_type_ok(); no remote protocol message carries that insn.\nAC:L - The attacker authors a SOCKET_FILTER program that does BPF_LOAD_ACQ of offsetof(__sk_buff, sk) with dst_reg==src_reg (the PTR_TO_CTX). check_load_mem() replaces that register with PTR_TO_SOCK_COMMON_OR_NULL, so type_is_sk_pointer() does not match and atomic_ptr_type_ok() accepts it. No race or uninfluenced layout is required.\nPR:L - bpf_prog_load() allows BPF_PROG_TYPE_SOCKET_FILTER and BPF_PROG_TYPE_CGROUP_SKB without CAP_BPF when sysctl_unprivileged_bpf_disabled is 0; otherwise bpf_token_capable(CAP_BPF) is enough. bpf_token_capable() uses ns_capable() on a delegated token userns, not init-namespace root. verifier_load_acquire.c marks socket load-acquire __success_unpriv.\nUI:N - The attacker loads the program with BPF_PROG_LOAD and runs it via BPF_PROG_TEST_RUN (bpf_prog_test_run_skb on sk_filter_prog_ops) or attaches it to their own socket with setsockopt(SO_ATTACH_BPF)\u2192sk_attach_bpf() and triggers the filter. No other user must mount or open a file.\nS:U - check_atomic_load()\u0027s type confusion and the later interpreter/JIT smp_load_acquire plus bpf_sock_convert_ctx_access loads run in the host kernel that accepted the program. That is in-kernel privilege escalation, not a KVM/Xen guest-to-host escape or IOMMU bypass.\nC:H - bpf_convert_ctx_accesses() does not rewrite BPF_ATOMIC, so load-acquire of offsetof(__sk_buff, sk) reads unconverted sk_buff bytes while the register is typed PTR_TO_SOCK_COMMON_OR_NULL. After a NULL check, later LDX of bpf_sock fields is rewritten by bpf_sock_convert_ctx_access() into struct sock loads against that pointer.\nI:H - The same confused PTR_TO_SOCK_COMMON is accepted as ARG_PTR_TO_SOCK_COMMON by bpf_sk_fullsock and, on CGROUP_SKB, bpf_sk_storage_get, which dereference and update sock-shaped kernel state on an object that is actually raw sk_buff memory. Commit-described verifier type confusion, not a bounded scalar leak.\nA:H - Interpreter BPF_LOAD_ACQ does smp_load_acquire of the unconverted ctx address, and follow-on bpf_sock_convert_ctx_access LDXes dereference that value as struct sock. A non-pointer or unmapped value page-faults in kernel context; the attacker can repeat this via BPF_PROG_TEST_RUN or the attached filter."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-18T17:54:29.867Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6ee7b00888498cf387dd30729e18a05328b94709"
        },
        {
          "url": "https://git.kernel.org/stable/c/422a416041172af1ac610736d5f556d22b31b115"
        },
        {
          "url": "https://git.kernel.org/stable/c/b87803391baa7e0bef60549d8841f12e549ad057"
        }
      ],
      "title": "bpf: Check load-acquire src ptr type before the load",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-90312",
    "datePublished": "2026-09-17T16:08:32.287Z",
    "dateReserved": "2026-09-11T19:38:34.801Z",
    "dateUpdated": "2026-09-18T17:54:29.867Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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FKIE_CVE-2026-90312

CVE-2026-90312 (GCVE-0-2026-90312)

Tags

Sightings

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