FKIE_CVE-2026-64192

Vulnerability from fkie_nvd - Published: 2026-07-20 17:18 - Updated: 2026-08-23 13:16
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject BPF_MAP_TYPE_INODE_STORAGE creation if BPF LSM is uninitialized When CONFIG_BPF_LSM=y is set, BPF inode storage maps (BPF_MAP_TYPE_INODE_STORAGE) are compiled into the kernel. However, if the BPF LSM is not explicitly enabled at boot time (e.g. omitted from the "lsm=" boot parameter), lsm_prepare() is never executed for the BPF LSM. Consequently, the BPF inode security blob offset (bpf_lsm_blob_sizes.lbs_inode) is never initialized and remains at its default compiled size of 8 bytes instead of being updated to a valid offset past the reserved struct rcu_head (typically 16 bytes or more). When a privileged user creates and updates a BPF_MAP_TYPE_INODE_STORAGE map, bpf_inode() evaluates inode->i_security + 8. This erroneously aliases the struct rcu_head.func callback pointer at the beginning of the inode->i_security blob. During subsequent map element cleanup or inode destruction, writing NULL to owner_storage clears the queued RCU callback pointer. When rcu_do_batch() later executes the queued callback, it attempts an instruction fetch at address 0x0, triggering an immediate kernel panic. Fix this by introducing a global bpf_lsm_initialized boolean flag marked with __ro_after_init. Set this flag to true inside bpf_lsm_init() when the LSM framework successfully registers the BPF LSM. Gate map allocation in inode_storage_map_alloc() on this flag, returning -EOPNOTSUPP if the BPF LSM is in turn uninitialized. This fail-fast approach prevents userspace from allocating inode storage maps when the supporting BPF LSM infrastructure is absent, avoiding zombie map states.
Impacted products

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "include/linux/bpf_lsm.h",
            "kernel/bpf/bpf_inode_storage.c",
            "security/bpf/hooks.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "413b14b9623a2e6ee131c2b2152b304aeb04e378",
              "status": "affected",
              "version": "8ea636848aca35b9f97c5b5dee30225cf2dd0fe6",
              "versionType": "git"
            },
            {
              "lessThan": "a6d634f794c808a261eac7d5af023a7e06b9ecd8",
              "status": "affected",
              "version": "8ea636848aca35b9f97c5b5dee30225cf2dd0fe6",
              "versionType": "git"
            },
            {
              "lessThan": "721f669853bdbf46b475a81bb5d05d610f8c19de",
              "status": "affected",
              "version": "8ea636848aca35b9f97c5b5dee30225cf2dd0fe6",
              "versionType": "git"
            },
            {
              "lessThan": "5337eebdf8c5d4810b1913047f078d2815d5645f",
              "status": "affected",
              "version": "8ea636848aca35b9f97c5b5dee30225cf2dd0fe6",
              "versionType": "git"
            },
            {
              "lessThan": "de984ea883405420fdc416ae8964b752df586970",
              "status": "affected",
              "version": "8ea636848aca35b9f97c5b5dee30225cf2dd0fe6",
              "versionType": "git"
            },
            {
              "lessThan": "267fdd9b6530c399dfd996e1a0a7628b45baf9f0",
              "status": "affected",
              "version": "8ea636848aca35b9f97c5b5dee30225cf2dd0fe6",
              "versionType": "git"
            },
            {
              "lessThan": "c76b8abce575e0c6e4096957220b4515ed847d89",
              "status": "affected",
              "version": "8ea636848aca35b9f97c5b5dee30225cf2dd0fe6",
              "versionType": "git"
            },
            {
              "lessThan": "a6f0643e4f63cfaa0d5d4a69de4f132eac4b8fe4",
              "status": "affected",
              "version": "8ea636848aca35b9f97c5b5dee30225cf2dd0fe6",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "include/linux/bpf_lsm.h",
            "kernel/bpf/bpf_inode_storage.c",
            "security/bpf/hooks.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.10"
            },
            {
              "lessThan": "5.10",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.266",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.217",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.184",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.148",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "5BE6BE06-D624-451A-964E-7A3DA481D745",
              "versionEndExcluding": "6.6.148",
              "versionStartIncluding": "5.10",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "05880CF6-5AD2-44E9-853A-6CE8318E76A5",
              "versionEndExcluding": "6.12.97",
              "versionStartIncluding": "6.7",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "67D87928-1419-4529-9201-42C059678CB4",
              "versionEndExcluding": "6.18.40",
              "versionStartIncluding": "6.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "6228DDD6-4557-4AA3-9F43-AB995D471E42",
              "versionEndExcluding": "7.1.4",
              "versionStartIncluding": "6.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:7.2:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "5E8B9085-7ADB-4A05-89EF-12949B6A0509",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject BPF_MAP_TYPE_INODE_STORAGE creation if BPF LSM is uninitialized\n\nWhen CONFIG_BPF_LSM=y is set, BPF inode storage maps\n(BPF_MAP_TYPE_INODE_STORAGE) are compiled into the kernel. However,\nif the BPF LSM is not explicitly enabled at boot time (e.g. omitted\nfrom the \"lsm=\" boot parameter), lsm_prepare() is never executed for\nthe BPF LSM.\n\nConsequently, the BPF inode security blob offset\n(bpf_lsm_blob_sizes.lbs_inode) is never initialized and remains at\nits default compiled size of 8 bytes instead of being updated to a\nvalid offset past the reserved struct rcu_head (typically 16 bytes\nor more).\n\nWhen a privileged user creates and updates a BPF_MAP_TYPE_INODE_STORAGE\nmap, bpf_inode() evaluates inode-\u003ei_security + 8. This erroneously\naliases the struct rcu_head.func callback pointer at the beginning\nof the inode-\u003ei_security blob. During subsequent map element cleanup\nor inode destruction, writing NULL to owner_storage clears the queued\nRCU callback pointer. When rcu_do_batch() later executes the queued\ncallback, it attempts an instruction fetch at address 0x0, triggering\nan immediate kernel panic.\n\nFix this by introducing a global bpf_lsm_initialized boolean flag\nmarked with __ro_after_init. Set this flag to true inside bpf_lsm_init()\nwhen the LSM framework successfully registers the BPF LSM. Gate map\nallocation in inode_storage_map_alloc() on this flag, returning\n-EOPNOTSUPP if the BPF LSM is in turn uninitialized.\n\nThis fail-fast approach prevents userspace from allocating inode\nstorage maps when the supporting BPF LSM infrastructure is absent,\navoiding zombie map states."
    }
  ],
  "id": "CVE-2026-64192",
  "lastModified": "2026-08-23T13:16:30.913",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 5.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2026-07-20T17:18:22.367",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/267fdd9b6530c399dfd996e1a0a7628b45baf9f0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/413b14b9623a2e6ee131c2b2152b304aeb04e378"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/5337eebdf8c5d4810b1913047f078d2815d5645f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/721f669853bdbf46b475a81bb5d05d610f8c19de"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a6d634f794c808a261eac7d5af023a7e06b9ecd8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/a6f0643e4f63cfaa0d5d4a69de4f132eac4b8fe4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/c76b8abce575e0c6e4096957220b4515ed847d89"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "tags": [
        "Patch"
      ],
      "url": "https://git.kernel.org/stable/c/de984ea883405420fdc416ae8964b752df586970"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-476"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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