Vulnerability-Lookup

GHSA-CMJX-92RG-PWQX

Vulnerability from github – Published: 2025-06-19 15:30 – Updated: 2025-09-22 21:30

Details

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

NFSv4: Fix free of uninitialized nfs4_label on referral lookup.

Send along the already-allocated fattr along with nfs4_fs_locations, and drop the memcpy of fattr. We end up growing two more allocations, but this fixes up a crash as:

PID: 790 TASK: ffff88811b43c000 CPU: 0 COMMAND: "ls" #0 [ffffc90000857920] panic at ffffffff81b9bfde #1 [ffffc900008579c0] do_trap at ffffffff81023a9b #2 [ffffc90000857a10] do_error_trap at ffffffff81023b78 #3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45 #4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de #5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs] #6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f #7 [ffffc90000857c60] walk_component at ffffffff813a86c4 #8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553 #9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b

Severity

5.5 (Medium)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2022-49418"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-908"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-02-26T07:01:18Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSv4: Fix free of uninitialized nfs4_label on referral lookup.\n\nSend along the already-allocated fattr along with nfs4_fs_locations, and\ndrop the memcpy of fattr.  We end up growing two more allocations, but this\nfixes up a crash as:\n\nPID: 790    TASK: ffff88811b43c000  CPU: 0   COMMAND: \"ls\"\n #0 [ffffc90000857920] panic at ffffffff81b9bfde\n #1 [ffffc900008579c0] do_trap at ffffffff81023a9b\n #2 [ffffc90000857a10] do_error_trap at ffffffff81023b78\n #3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45\n #4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de\n #5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs]\n #6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f\n #7 [ffffc90000857c60] walk_component at ffffffff813a86c4\n #8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553\n #9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b",
  "id": "GHSA-cmjx-92rg-pwqx",
  "modified": "2025-09-22T21:30:17Z",
  "published": "2025-06-19T15:30:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49418"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6015292653d95ba9f72906e2b65e536aa5807d64"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c3ed222745d9ad7b69299b349a64ba533c64a34f"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2022-49418 (GCVE-0-2022-49418)

Vulnerability from cvelistv5 – Published: 2025-02-26 02:12 – Updated: 2026-08-05 08:55

Title

NFSv4: Fix free of uninitialized nfs4_label on referral lookup.

Summary

In the Linux kernel, the following vulnerability has been resolved: NFSv4: Fix free of uninitialized nfs4_label on referral lookup. Send along the already-allocated fattr along with nfs4_fs_locations, and drop the memcpy of fattr. We end up growing two more allocations, but this fixes up a crash as: PID: 790 TASK: ffff88811b43c000 CPU: 0 COMMAND: "ls" #0 [ffffc90000857920] panic at ffffffff81b9bfde #1 [ffffc900008579c0] do_trap at ffffffff81023a9b #2 [ffffc90000857a10] do_error_trap at ffffffff81023b78 #3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45 #4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de #5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs] #6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f #7 [ffffc90000857c60] walk_component at ffffffff813a86c4 #8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553 #9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b

Severity

9.8 (Critical)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/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/6015292653d95ba9f…
https://git.kernel.org/stable/c/c3ed222745d9ad7b6…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 9558a007dbc383d48e7f5a123d0b5ff656c71068 , < 6015292653d95ba9f72906e2b65e536aa5807d64 (git) Affected: 9558a007dbc383d48e7f5a123d0b5ff656c71068 , < c3ed222745d9ad7b69299b349a64ba533c64a34f (git)
Linux	Linux	Affected: 5.16 Unaffected: 0 , < 5.16 (semver) Unaffected: 5.18.3 , ≤ 5.18.* (semver) Unaffected: 5.19 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/nfs/nfs4namespace.c",
            "fs/nfs/nfs4proc.c",
            "fs/nfs/nfs4state.c",
            "fs/nfs/nfs4xdr.c",
            "include/linux/nfs_xdr.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6015292653d95ba9f72906e2b65e536aa5807d64",
              "status": "affected",
              "version": "9558a007dbc383d48e7f5a123d0b5ff656c71068",
              "versionType": "git"
            },
            {
              "lessThan": "c3ed222745d9ad7b69299b349a64ba533c64a34f",
              "status": "affected",
              "version": "9558a007dbc383d48e7f5a123d0b5ff656c71068",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/nfs/nfs4namespace.c",
            "fs/nfs/nfs4proc.c",
            "fs/nfs/nfs4state.c",
            "fs/nfs/nfs4xdr.c",
            "include/linux/nfs_xdr.h"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.16"
            },
            {
              "lessThan": "5.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.18.*",
              "status": "unaffected",
              "version": "5.18.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "5.19",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.18.3",
                  "versionStartIncluding": "5.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.19",
                  "versionStartIncluding": "5.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nNFSv4: Fix free of uninitialized nfs4_label on referral lookup.\n\nSend along the already-allocated fattr along with nfs4_fs_locations, and\ndrop the memcpy of fattr.  We end up growing two more allocations, but this\nfixes up a crash as:\n\nPID: 790    TASK: ffff88811b43c000  CPU: 0   COMMAND: \"ls\"\n #0 [ffffc90000857920] panic at ffffffff81b9bfde\n #1 [ffffc900008579c0] do_trap at ffffffff81023a9b\n #2 [ffffc90000857a10] do_error_trap at ffffffff81023b78\n #3 [ffffc90000857a58] exc_stack_segment at ffffffff81be1f45\n #4 [ffffc90000857a80] asm_exc_stack_segment at ffffffff81c009de\n #5 [ffffc90000857b08] nfs_lookup at ffffffffa0302322 [nfs]\n #6 [ffffc90000857b70] __lookup_slow at ffffffff813a4a5f\n #7 [ffffc90000857c60] walk_component at ffffffff813a86c4\n #8 [ffffc90000857cb8] path_lookupat at ffffffff813a9553\n #9 [ffffc90000857cf0] filename_lookup at ffffffff813ab86b"
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The bug is in the NFSv4 client referral path (fs/nfs): a malicious or compromised NFS server drives it by returning NFS4ERR_MOVED on LOOKUP and a successful FS_LOCATIONS reply with a different fsid over the network.\nAC:L - The remote server fully controls when MOVED/referral replies are sent and can trigger the path deterministically; CONFIG_NFS_V4_SECURITY_LABEL defaults to y, so the uninitialized-label free is not gated on a rare config.\nPR:N - Exploitation is from the remote NFS peer (or on-path AUTH_SYS attacker) with no account or capability on the victim client; no client-side privileges are required beyond an existing NFSv4 mount relationship.\nUI:N - An already-mounted NFSv4 export plus ordinary client lookups/revalidations (or automount activity) is enough; the malicious server can wait for routine pathwalks without a distinct victim action at exploit time.\nS:U - The uninitialized free and resulting heap corruption stay in the client kernel address space within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - memcpy replaces a valid fattr-\u003elabel with uninitialized kmalloc garbage, then nfs4_label_free dereferences that pointer (kfree(label-\u003elabel)/kfree(label)), yielding memory-corruption primitives that can disclose kernel memory when the freed object is reclaimed.\nI:H - Freeing an uninitialized nfs4_label pointer is an arbitrary/corrupt free suitable for heap manipulation and control-flow hijacking, consistent with treating this class of memory corruption as high integrity impact.\nA:H - The reported crash is a kernel panic/oops in nfs_lookup (exc_stack_segment) when the garbage label is freed, and the corruption is repeatable whenever the server returns a referral."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T08:55:09.630Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6015292653d95ba9f72906e2b65e536aa5807d64"
        },
        {
          "url": "https://git.kernel.org/stable/c/c3ed222745d9ad7b69299b349a64ba533c64a34f"
        }
      ],
      "title": "NFSv4: Fix free of uninitialized nfs4_label on referral lookup.",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2022-49418",
    "datePublished": "2025-02-26T02:12:43.359Z",
    "dateReserved": "2025-02-26T02:08:31.568Z",
    "dateUpdated": "2026-08-05T08:55:09.630Z",
    "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.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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