Vulnerability-Lookup

GHSA-7JH9-V3VW-V9PX

Vulnerability from github – Published: 2024-10-21 12:30 – Updated: 2024-10-22 18:32

Details

In the Linux kernel, the following vulnerability has been resolved:

mm/hugetlb.c: fix UAF of vma in hugetlb fault pathway

Syzbot reports a UAF in hugetlb_fault(). This happens because vmf_anon_prepare() could drop the per-VMA lock and allow the current VMA to be freed before hugetlb_vma_unlock_read() is called.

We can fix this by using a modified version of vmf_anon_prepare() that doesn't release the VMA lock on failure, and then release it ourselves after hugetlb_vma_unlock_read().

Severity

7.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2024-47676"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-416"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-10-21T12:15:04Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/hugetlb.c: fix UAF of vma in hugetlb fault pathway\n\nSyzbot reports a UAF in hugetlb_fault().  This happens because\nvmf_anon_prepare() could drop the per-VMA lock and allow the current VMA\nto be freed before hugetlb_vma_unlock_read() is called.\n\nWe can fix this by using a modified version of vmf_anon_prepare() that\ndoesn\u0027t release the VMA lock on failure, and then release it ourselves\nafter hugetlb_vma_unlock_read().",
  "id": "GHSA-7jh9-v3vw-v9px",
  "modified": "2024-10-22T18:32:09Z",
  "published": "2024-10-21T12:30:54Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-47676"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/98b74bb4d7e96b4da5ef3126511febe55b76b807"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d59ebc99dee0a2687a26df94b901eb8216dbf876"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e897d184a8dd4a4e1f39c8c495598e4d9472776c"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2024-47676 (GCVE-0-2024-47676)

Vulnerability from cvelistv5 – Published: 2024-10-21 11:53 – Updated: 2026-08-05 11:39

Title

mm/hugetlb.c: fix UAF of vma in hugetlb fault pathway

Summary

In the Linux kernel, the following vulnerability has been resolved: mm/hugetlb.c: fix UAF of vma in hugetlb fault pathway Syzbot reports a UAF in hugetlb_fault(). This happens because vmf_anon_prepare() could drop the per-VMA lock and allow the current VMA to be freed before hugetlb_vma_unlock_read() is called. We can fix this by using a modified version of vmf_anon_prepare() that doesn't release the VMA lock on failure, and then release it ourselves after hugetlb_vma_unlock_read().

Severity

7.8 (High)


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

SSVC

Exploitation: none Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-10-21 13:07 UTC

Assigner

Linux mitre root

References

3 references

URL	Tags
https://git.kernel.org/stable/c/e897d184a8dd4a4e1…
https://git.kernel.org/stable/c/d59ebc99dee0a2687…
https://git.kernel.org/stable/c/98b74bb4d7e96b4da…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 9acad7ba3e25d11f4c96df1b7312ae89e6faca5c , < e897d184a8dd4a4e1f39c8c495598e4d9472776c (git) Affected: 9acad7ba3e25d11f4c96df1b7312ae89e6faca5c , < d59ebc99dee0a2687a26df94b901eb8216dbf876 (git) Affected: 9acad7ba3e25d11f4c96df1b7312ae89e6faca5c , < 98b74bb4d7e96b4da5ef3126511febe55b76b807 (git)
Linux	Linux	Affected: 6.9 Unaffected: 0 , < 6.9 (semver) Unaffected: 6.10.13 , ≤ 6.10.* (semver) Unaffected: 6.11.2 , ≤ 6.11.* (semver) Unaffected: 6.12 , ≤ * (original_commit_for_fix)

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              "content": {
                "id": "CVE-2024-47676",
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                "timestamp": "2024-10-21T13:07:59.972172Z",
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          "shortName": "CISA-ADP"
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              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.12",
              "versionType": "original_commit_for_fix"
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        }
      ],
      "cpeApplicability": [
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          "nodes": [
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              "cpeMatch": [
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        }
      ],
      "metrics": [
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              "value": "AV:L - The vulnerability is triggered by a page fault on a hugetlb mapping in the attacker\u0027s own address space, requiring local execution of code on the target system. There is no network-reachable path into `hugetlb_fault()`.\nAC:L - The attacker controls every side of the race \u2014 the faulting thread, the sibling thread holding `mmap_lock` for write that forces `mmap_read_trylock()` to fail, and the `munmap()` thread that frees the VMA \u2014 and can retry the fault indefinitely. Syzbot reproduced the UAF, confirming it is reliably triggerable.\nPR:L - Any unprivileged local user can create the required private hugetlb VMA via `memfd_create(MFD_HUGETLB)` or `mmap(MAP_HUGETLB|MAP_NORESERVE)` with no capability check, and the UAF path in `hugetlb_no_page()` is reached before any hugepage allocation is attempted. No CAP_* or root is needed.\nUI:N - The attacker\u0027s own threads perform the mapping, faulting, and unmapping entirely on their own; no victim action or interaction of any kind is required.\nS:U - The corruption is of a `vm_area_struct` in kernel slab memory belonging to the attacker\u0027s own mm, handled by the kernel itself. It is a standard in-kernel memory-safety issue with no crossing of a VM, IOMMU, or other security-authority boundary.\nC:H - After the VMA is freed, `hugetlb_vma_unlock_read()` reads `vma-\u003evm_flags` and `vma-\u003evm_private_data` from reclaimed slab memory, so an attacker who grooms the freed `vm_area_struct` can steer subsequent dereferences and leverage the UAF for kernel memory disclosure.\nI:H - The stale `vma-\u003evm_private_data` is used as a `hugetlb_vma_lock`/`resv_map` pointer and `up_read()` performs an atomic decrement plus possible waiter-list manipulation at that attacker-influenced address, giving a controllable kernel write primitive suitable for privilege escalation via heap spraying.\nA:H - Dereferencing a freed `vm_area_struct` and operating an rwsem derived from reclaimed memory readily causes kernel oops, rwsem-state corruption, or panic, and the attacker can trigger it repeatedly at will."
            }
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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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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