Vulnerability-Lookup

FKIE_CVE-2026-72112

Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-17 06:18

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: io_uring/bpf-ops: reject re-registration of an already-bound ops io_install_bpf() only rejects a second registration on the ctx side (ctx->bpf_ops) and sets the per-map back-pointer ops->priv unconditionally. The struct_ops link path never advances a map past BPF_STRUCT_OPS_STATE_READY, so the same io_uring_bpf_ops map can be registered more than once, and bpf_io_reg() re-resolves the target ring via fget(ops->ring_fd) on every call. A caller can therefore point the same ring_fd at a different io_ring_ctx between two BPF_LINK_CREATE calls. The second registration passes the ctx->bpf_ops check (the new ctx has none) and overwrites ops->priv, orphaning the first ctx. Teardown (io_eject_bpf()/bpf_io_unreg()) only reaches a ctx through ops->priv, so the orphaned ctx is never torn down: its ctx->loop_step keeps pointing into the struct_ops trampoline, which is freed once the map is gone. A later io_uring_enter() on the orphaned ring then calls the dangling ctx->loop_step from io_run_loop() -- a use-after-free of freed executable memory, reachable by a task with CAP_BPF + CAP_PERFMON. Reject registration when ops->priv is already set, as hid_bpf_reg() does for its struct_ops.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/0639ea767fe04c288a8d6cb826100fe3d95d4936
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/3afc64c61ce906a04f073ca350b46de10e8302f9

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "io_uring/bpf-ops.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "0639ea767fe04c288a8d6cb826100fe3d95d4936",
              "status": "affected",
              "version": "98f37634b12b17ad5c56db8fb63cf9d7dc55d74c",
              "versionType": "git"
            },
            {
              "lessThan": "3afc64c61ce906a04f073ca350b46de10e8302f9",
              "status": "affected",
              "version": "98f37634b12b17ad5c56db8fb63cf9d7dc55d74c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "io_uring/bpf-ops.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": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "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\nio_uring/bpf-ops: reject re-registration of an already-bound ops\n\nio_install_bpf() only rejects a second registration on the ctx side\n(ctx-\u003ebpf_ops) and sets the per-map back-pointer ops-\u003epriv\nunconditionally. The struct_ops link path never advances a map past\nBPF_STRUCT_OPS_STATE_READY, so the same io_uring_bpf_ops map can be\nregistered more than once, and bpf_io_reg() re-resolves the target ring\nvia fget(ops-\u003ering_fd) on every call. A caller can therefore point the\nsame ring_fd at a different io_ring_ctx between two BPF_LINK_CREATE\ncalls.\n\nThe second registration passes the ctx-\u003ebpf_ops check (the new ctx has\nnone) and overwrites ops-\u003epriv, orphaning the first ctx. Teardown\n(io_eject_bpf()/bpf_io_unreg()) only reaches a ctx through ops-\u003epriv, so\nthe orphaned ctx is never torn down: its ctx-\u003eloop_step keeps pointing\ninto the struct_ops trampoline, which is freed once the map is gone. A\nlater io_uring_enter() on the orphaned ring then calls the dangling\nctx-\u003eloop_step from io_run_loop() -- a use-after-free of freed\nexecutable memory, reachable by a task with CAP_BPF + CAP_PERFMON.\n\nReject registration when ops-\u003epriv is already set, as hid_bpf_reg()\ndoes for its struct_ops."
    }
  ],
  "id": "CVE-2026-72112",
  "lastModified": "2026-08-17T06:18:10.417",
  "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": "2026-08-15T06:21:25.563",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/0639ea767fe04c288a8d6cb826100fe3d95d4936"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3afc64c61ce906a04f073ca350b46de10e8302f9"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-72112 (GCVE-0-2026-72112)

Vulnerability from cvelistv5 – Published: 2026-08-15 05:52 – Updated: 2026-08-17 05:40

Title

io_uring/bpf-ops: reject re-registration of an already-bound ops

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

2 references

URL	Tags
https://git.kernel.org/stable/c/0639ea767fe04c288…
https://git.kernel.org/stable/c/3afc64c61ce906a04…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 98f37634b12b17ad5c56db8fb63cf9d7dc55d74c , < 0639ea767fe04c288a8d6cb826100fe3d95d4936 (git) Affected: 98f37634b12b17ad5c56db8fb63cf9d7dc55d74c , < 3afc64c61ce906a04f073ca350b46de10e8302f9 (git)
Linux	Linux	Affected: 7.1 Unaffected: 0 , < 7.1 (semver) Unaffected: 7.1.5 , ≤ 7.1.* (semver) Unaffected: 7.2 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "io_uring/bpf-ops.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "0639ea767fe04c288a8d6cb826100fe3d95d4936",
              "status": "affected",
              "version": "98f37634b12b17ad5c56db8fb63cf9d7dc55d74c",
              "versionType": "git"
            },
            {
              "lessThan": "3afc64c61ce906a04f073ca350b46de10e8302f9",
              "status": "affected",
              "version": "98f37634b12b17ad5c56db8fb63cf9d7dc55d74c",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "io_uring/bpf-ops.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": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "7.1",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/bpf-ops: reject re-registration of an already-bound ops\n\nio_install_bpf() only rejects a second registration on the ctx side\n(ctx-\u003ebpf_ops) and sets the per-map back-pointer ops-\u003epriv\nunconditionally. The struct_ops link path never advances a map past\nBPF_STRUCT_OPS_STATE_READY, so the same io_uring_bpf_ops map can be\nregistered more than once, and bpf_io_reg() re-resolves the target ring\nvia fget(ops-\u003ering_fd) on every call. A caller can therefore point the\nsame ring_fd at a different io_ring_ctx between two BPF_LINK_CREATE\ncalls.\n\nThe second registration passes the ctx-\u003ebpf_ops check (the new ctx has\nnone) and overwrites ops-\u003epriv, orphaning the first ctx. Teardown\n(io_eject_bpf()/bpf_io_unreg()) only reaches a ctx through ops-\u003epriv, so\nthe orphaned ctx is never torn down: its ctx-\u003eloop_step keeps pointing\ninto the struct_ops trampoline, which is freed once the map is gone. A\nlater io_uring_enter() on the orphaned ring then calls the dangling\nctx-\u003eloop_step from io_run_loop() -- a use-after-free of freed\nexecutable memory, reachable by a task with CAP_BPF + CAP_PERFMON.\n\nReject registration when ops-\u003epriv is already set, as hid_bpf_reg()\ndoes for its struct_ops."
        }
      ],
      "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 bug is reached only through local bpf() syscalls (BPF_MAP_CREATE/UPDATE_ELEM, BPF_PROG_LOAD, BPF_LINK_CREATE) and io_uring_setup/io_uring_enter on an orphaned ring; per kernel guidance io_uring and BPF are Local attack vectors with no remote packet path.\nAC:L - Exploitation is fully deterministic and attacker-controlled: create two DEFER_TASKRUN rings, link the same struct_ops map twice after dup2 repointing ring_fd, free the map/link, then io_uring_enter on the orphaned ring; no race or conditions outside attacker control are required.\nPR:L - The commit requires CAP_BPF and CAP_PERFMON, but bpf_token_capable() can delegate these into non-init user namespaces via BPF tokens in containerized deployments, and io_uring is commonly available to local users; under uncertainty this is scored Low rather than High.\nUI:N - No victim interaction is needed; once the attacker has BPF and io_uring access they can perform every setup, teardown, and triggering step themselves without any other user opening files or taking action.\nS:U - Impact is confined to kernel memory and execution within the same kernel security authority (standard local privilege-escalation/memory-corruption class), not a VM escape, IOMMU bypass, or other cross-scope boundary.\nC:H - Orphaned ctx-\u003eloop_step retains a pointer into a freed BPF struct_ops trampoline page; executing or dereferencing that UAF can expose reclaimed slab contents and supports building arbitrary read primitives, so confidentiality impact is High per UAF guidance.\nI:H - The dangling loop_step calls freed executable trampoline memory from io_run_loop(); with heap grooming an attacker can reclaim those pages with controlled contents, enabling control-flow hijack and arbitrary kernel write, so integrity impact is High.\nA:H - Invoking the dangling ctx-\u003eloop_step after trampoline teardown causes use-after-free of executable kernel memory during io_uring_enter, which can reliably trigger kernel oops, BUG, or panic and is repeatable on demand."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-17T05:40:26.740Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/0639ea767fe04c288a8d6cb826100fe3d95d4936"
        },
        {
          "url": "https://git.kernel.org/stable/c/3afc64c61ce906a04f073ca350b46de10e8302f9"
        }
      ],
      "title": "io_uring/bpf-ops: reject re-registration of an already-bound ops",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-72112",
    "datePublished": "2026-08-15T05:52:53.275Z",
    "dateReserved": "2026-08-09T03:40:39.906Z",
    "dateUpdated": "2026-08-17T05:40:26.740Z",
    "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.

Detection rules are retrieved from Rulezet.

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-2026-72112

CVE-2026-72112 (GCVE-0-2026-72112)

Tags

Sightings

Nomenclature