GSD-2021-47125

Vulnerability from gsd - Updated: 2024-03-05 06:03
Details
In the Linux kernel, the following vulnerability has been resolved: sch_htb: fix refcount leak in htb_parent_to_leaf_offload The commit ae81feb7338c ("sch_htb: fix null pointer dereference on a null new_q") fixes a NULL pointer dereference bug, but it is not correct. Because htb_graft_helper properly handles the case when new_q is NULL, and after the previous patch by skipping this call which creates an inconsistency : dev_queue->qdisc will still point to the old qdisc, but cl->parent->leaf.q will point to the new one (which will be noop_qdisc, because new_q was NULL). The code is based on an assumption that these two pointers are the same, so it can lead to refcount leaks. The correct fix is to add a NULL pointer check to protect qdisc_refcount_inc inside htb_parent_to_leaf_offload.
Aliases
To clipboard 

{
  "gsd": {
    "metadata": {
      "exploitCode": "unknown",
      "remediation": "unknown",
      "reportConfidence": "confirmed",
      "type": "vulnerability"
    },
    "osvSchema": {
      "aliases": [
        "CVE-2021-47125"
      ],
      "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsch_htb: fix refcount leak in htb_parent_to_leaf_offload\n\nThe commit ae81feb7338c (\"sch_htb: fix null pointer dereference\non a null new_q\") fixes a NULL pointer dereference bug, but it\nis not correct.\n\nBecause htb_graft_helper properly handles the case when new_q\nis NULL, and after the previous patch by skipping this call\nwhich creates an inconsistency : dev_queue-\u003eqdisc will still\npoint to the old qdisc, but cl-\u003eparent-\u003eleaf.q will point to\nthe new one (which will be noop_qdisc, because new_q was NULL).\nThe code is based on an assumption that these two pointers are\nthe same, so it can lead to refcount leaks.\n\nThe correct fix is to add a NULL pointer check to protect\nqdisc_refcount_inc inside htb_parent_to_leaf_offload.",
      "id": "GSD-2021-47125",
      "modified": "2024-03-05T06:03:55.096372Z",
      "schema_version": "1.4.0"
    }
  },
  "namespaces": {
    "cve.org": {
      "CVE_data_meta": {
        "ASSIGNER": "cve@kernel.org",
        "ID": "CVE-2021-47125",
        "STATE": "PUBLIC"
      },
      "affects": {
        "vendor": {
          "vendor_data": [
            {
              "product": {
                "product_data": [
                  {
                    "product_name": "Linux",
                    "version": {
                      "version_data": [
                        {
                          "version_affected": "\u003c",
                          "version_name": "ae81feb7338c",
                          "version_value": "2411c02d0389"
                        },
                        {
                          "version_value": "not down converted",
                          "x_cve_json_5_version_data": {
                            "defaultStatus": "affected",
                            "versions": [
                              {
                                "status": "affected",
                                "version": "5.12"
                              },
                              {
                                "lessThan": "5.12",
                                "status": "unaffected",
                                "version": "0",
                                "versionType": "custom"
                              },
                              {
                                "lessThanOrEqual": "5.12.*",
                                "status": "unaffected",
                                "version": "5.12.10",
                                "versionType": "custom"
                              },
                              {
                                "lessThanOrEqual": "*",
                                "status": "unaffected",
                                "version": "5.13",
                                "versionType": "original_commit_for_fix"
                              }
                            ]
                          }
                        }
                      ]
                    }
                  }
                ]
              },
              "vendor_name": "Linux"
            }
          ]
        }
      },
      "data_format": "MITRE",
      "data_type": "CVE",
      "data_version": "4.0",
      "description": {
        "description_data": [
          {
            "lang": "eng",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsch_htb: fix refcount leak in htb_parent_to_leaf_offload\n\nThe commit ae81feb7338c (\"sch_htb: fix null pointer dereference\non a null new_q\") fixes a NULL pointer dereference bug, but it\nis not correct.\n\nBecause htb_graft_helper properly handles the case when new_q\nis NULL, and after the previous patch by skipping this call\nwhich creates an inconsistency : dev_queue-\u003eqdisc will still\npoint to the old qdisc, but cl-\u003eparent-\u003eleaf.q will point to\nthe new one (which will be noop_qdisc, because new_q was NULL).\nThe code is based on an assumption that these two pointers are\nthe same, so it can lead to refcount leaks.\n\nThe correct fix is to add a NULL pointer check to protect\nqdisc_refcount_inc inside htb_parent_to_leaf_offload."
          }
        ]
      },
      "generator": {
        "engine": "bippy-8df59b4913de"
      },
      "problemtype": {
        "problemtype_data": [
          {
            "description": [
              {
                "lang": "eng",
                "value": "n/a"
              }
            ]
          }
        ]
      },
      "references": {
        "reference_data": [
          {
            "name": "https://git.kernel.org/stable/c/2411c02d03892a5057499f8102d0cc1e0f852416",
            "refsource": "MISC",
            "url": "https://git.kernel.org/stable/c/2411c02d03892a5057499f8102d0cc1e0f852416"
          },
          {
            "name": "https://git.kernel.org/stable/c/944d671d5faa0d78980a3da5c0f04960ef1ad893",
            "refsource": "MISC",
            "url": "https://git.kernel.org/stable/c/944d671d5faa0d78980a3da5c0f04960ef1ad893"
          }
        ]
      }
    },
    "nvd.nist.gov": {
      "cve": {
        "descriptions": [
          {
            "lang": "en",
            "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsch_htb: fix refcount leak in htb_parent_to_leaf_offload\n\nThe commit ae81feb7338c (\"sch_htb: fix null pointer dereference\non a null new_q\") fixes a NULL pointer dereference bug, but it\nis not correct.\n\nBecause htb_graft_helper properly handles the case when new_q\nis NULL, and after the previous patch by skipping this call\nwhich creates an inconsistency : dev_queue-\u003eqdisc will still\npoint to the old qdisc, but cl-\u003eparent-\u003eleaf.q will point to\nthe new one (which will be noop_qdisc, because new_q was NULL).\nThe code is based on an assumption that these two pointers are\nthe same, so it can lead to refcount leaks.\n\nThe correct fix is to add a NULL pointer check to protect\nqdisc_refcount_inc inside htb_parent_to_leaf_offload."
          }
        ],
        "id": "CVE-2021-47125",
        "lastModified": "2024-03-17T22:38:29.433",
        "metrics": {},
        "published": "2024-03-15T21:15:07.307",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/2411c02d03892a5057499f8102d0cc1e0f852416"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/944d671d5faa0d78980a3da5c0f04960ef1ad893"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Awaiting Analysis"
      }
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.