CVE-2026-93099 (GCVE-0-2026-93099)

Vulnerability from cvelistv5 – Published: 2026-09-17 16:11 – Updated: 2026-10-19 09:05
VLAI
Title
fs/resctrl: Fix UAF from worker threads when domains are removed
Summary
In the Linux kernel, the following vulnerability has been resolved: fs/resctrl: Fix UAF from worker threads when domains are removed The mbm_handle_overflow() and cqm_handle_limbo() workers read event counters and may sleep while doing so. They are scheduled via delayed_work embedded in struct rdt_l3_mon_domain. Architecture allocates and frees these domains from CPU hotplug callbacks under cpus_write_lock(), and the workers acquire cpus_read_lock() to keep the domain alive across their access. A use-after-free can occur when a worker is blocked waiting for cpus_read_lock() while the hotplug core holds cpus_write_lock(): the architecture frees the rdt_l3_mon_domain that contains the worker's work_struct. When the worker unblocks, the container_of() it performs on the embedded work pointer dereferences freed memory. Drop cpus_read_lock() from the workers and instead drain pending and in-flight work synchronously before the architecture can free the domain. Since architecture offlines the domain under cpus_write_lock() after it has been unlinked from the RCU list and a grace period has elapsed, no new work can be scheduled. The cancel only needs to wait out existing work. Drop rdtgroup_mutex during CPU offline around cancel_delayed_work_sync() so that a worker waiting on the mutex can complete before re-pinning the work on a different CPU. When offlining a CPU the architecture may iterate over resources in any order. For example, the MBA control domain may be offlined before or after a corresponding L3 monitor domain. Ensure that resctrl fs cancels the workers no matter what order the architecture offlines the domains.
Severity
No CVSS data available.
Assigner
Linux CNA under the mitre root
CNA scorecard D 53/100 over 7056 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 24247aeeabe99eab13b798ccccc2dec066dd6f07 , < 6a2e023429a41afd0d9dfe74268aa51774a953ff (git)
Affected: 24247aeeabe99eab13b798ccccc2dec066dd6f07 , < b86dbfe4583bf134932a6cc45bf25b12c10a0b2f (git)
Affected: 24247aeeabe99eab13b798ccccc2dec066dd6f07 , < 2566b5cd6a275c124e8f154fef6e815f92ec8d5c (git)
guessed Create a notification for this product.
Linux Linux Affected: 4.14
Unaffected: 0 , < 4.14 (semver)
Unaffected: 6.18.57 , ≤ 6.18.* (semver)
Unaffected: 7.2.6 , ≤ 7.2.* (semver)
Unaffected: 7.3 , ≤ * (original_commit_for_fix)
guessed Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/resctrl/monitor.c",
            "fs/resctrl/rdtgroup.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6a2e023429a41afd0d9dfe74268aa51774a953ff",
              "status": "affected",
              "version": "24247aeeabe99eab13b798ccccc2dec066dd6f07",
              "versionType": "git"
            },
            {
              "lessThan": "b86dbfe4583bf134932a6cc45bf25b12c10a0b2f",
              "status": "affected",
              "version": "24247aeeabe99eab13b798ccccc2dec066dd6f07",
              "versionType": "git"
            },
            {
              "lessThan": "2566b5cd6a275c124e8f154fef6e815f92ec8d5c",
              "status": "affected",
              "version": "24247aeeabe99eab13b798ccccc2dec066dd6f07",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/resctrl/monitor.c",
            "fs/resctrl/rdtgroup.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.14"
            },
            {
              "lessThan": "4.14",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.57",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.57",
                  "versionStartIncluding": "4.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.6",
                  "versionStartIncluding": "4.14",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "4.14",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nfs/resctrl: Fix UAF from worker threads when domains are removed\n\nThe mbm_handle_overflow() and cqm_handle_limbo() workers read event counters\nand may sleep while doing so. They are scheduled via delayed_work embedded in\nstruct rdt_l3_mon_domain. Architecture allocates and frees these domains from\nCPU hotplug callbacks under cpus_write_lock(), and the workers acquire\ncpus_read_lock() to keep the domain alive across their access.\n\nA use-after-free can occur when a worker is blocked waiting for\ncpus_read_lock() while the hotplug core holds cpus_write_lock(): the\narchitecture frees the rdt_l3_mon_domain that contains the worker\u0027s\nwork_struct. When the worker unblocks, the container_of() it performs on the\nembedded work pointer dereferences freed memory.\n\nDrop cpus_read_lock() from the workers and instead drain pending and in-flight\nwork synchronously before the architecture can free the domain.  Since\narchitecture offlines the domain under cpus_write_lock() after it has been\nunlinked from the RCU list and a grace period has elapsed, no new work can be\nscheduled. The cancel only needs to wait out existing work.  Drop\nrdtgroup_mutex during CPU offline around cancel_delayed_work_sync() so that\na worker waiting on the mutex can complete before re-pinning the work on\na different CPU.\n\nWhen offlining a CPU the architecture may iterate over resources in any order.\nFor example, the MBA control domain may be offlined before or after\na corresponding L3 monitor domain. Ensure that resctrl fs cancels the workers\nno matter what order the architecture offlines the domains."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:05:32.346Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/6a2e023429a41afd0d9dfe74268aa51774a953ff"
        },
        {
          "url": "https://git.kernel.org/stable/c/b86dbfe4583bf134932a6cc45bf25b12c10a0b2f"
        },
        {
          "url": "https://git.kernel.org/stable/c/2566b5cd6a275c124e8f154fef6e815f92ec8d5c"
        }
      ],
      "title": "fs/resctrl: Fix UAF from worker threads when domains are removed",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-93099",
    "datePublished": "2026-09-17T16:11:12.373Z",
    "dateReserved": "2026-09-17T16:02:15.084Z",
    "dateUpdated": "2026-10-19T09:05:32.346Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-93099",
      "date": "2026-10-24",
      "epss": "0.00206",
      "percentile": "0.10149"
    },
    "microsoft_vex": {
      "current_release_date": "2026-10-21T18:32:50.000Z",
      "cve": "CVE-2026-93099",
      "id": "msrc_CVE-2026-93099",
      "initial_release_date": "2026-09-19T01:08:22.000Z",
      "product_status:known_affected": "3",
      "product_status:under_investigation": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "fs/resctrl: Fix UAF from worker threads when domains are removed",
      "url": "https://msrc.microsoft.com/csaf/vex/2026/msrc_cve-2026-93099.json",
      "version": "5"
    },
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "defaultStatus": "unaffected",
                "product": "Linux",
                "programFiles": [
                  "fs/resctrl/monitor.c",
                  "fs/resctrl/rdtgroup.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "lessThan": "6a2e023429a41afd0d9dfe74268aa51774a953ff",
                    "status": "affected",
                    "version": "24247aeeabe99eab13b798ccccc2dec066dd6f07",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "b86dbfe4583bf134932a6cc45bf25b12c10a0b2f",
                    "status": "affected",
                    "version": "24247aeeabe99eab13b798ccccc2dec066dd6f07",
                    "versionType": "git"
                  },
                  {
                    "lessThan": "2566b5cd6a275c124e8f154fef6e815f92ec8d5c",
                    "status": "affected",
                    "version": "24247aeeabe99eab13b798ccccc2dec066dd6f07",
                    "versionType": "git"
                  }
                ]
              },
              {
                "defaultStatus": "affected",
                "product": "Linux",
                "programFiles": [
                  "fs/resctrl/monitor.c",
                  "fs/resctrl/rdtgroup.c"
                ],
                "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                "vendor": "Linux",
                "versions": [
                  {
                    "status": "affected",
                    "version": "4.14"
                  },
                  {
                    "lessThan": "4.14",
                    "status": "unaffected",
                    "version": "0",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "6.18.*",
                    "status": "unaffected",
                    "version": "6.18.57",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "7.2.*",
                    "status": "unaffected",
                    "version": "7.2.6",
                    "versionType": "semver"
                  },
                  {
                    "lessThanOrEqual": "*",
                    "status": "unaffected",
                    "version": "7.3",
                    "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\nfs/resctrl: Fix UAF from worker threads when domains are removed\n\nThe mbm_handle_overflow() and cqm_handle_limbo() workers read event counters\nand may sleep while doing so. They are scheduled via delayed_work embedded in\nstruct rdt_l3_mon_domain. Architecture allocates and frees these domains from\nCPU hotplug callbacks under cpus_write_lock(), and the workers acquire\ncpus_read_lock() to keep the domain alive across their access.\n\nA use-after-free can occur when a worker is blocked waiting for\ncpus_read_lock() while the hotplug core holds cpus_write_lock(): the\narchitecture frees the rdt_l3_mon_domain that contains the worker\u0027s\nwork_struct. When the worker unblocks, the container_of() it performs on the\nembedded work pointer dereferences freed memory.\n\nDrop cpus_read_lock() from the workers and instead drain pending and in-flight\nwork synchronously before the architecture can free the domain.  Since\narchitecture offlines the domain under cpus_write_lock() after it has been\nunlinked from the RCU list and a grace period has elapsed, no new work can be\nscheduled. The cancel only needs to wait out existing work.  Drop\nrdtgroup_mutex during CPU offline around cancel_delayed_work_sync() so that\na worker waiting on the mutex can complete before re-pinning the work on\na different CPU.\n\nWhen offlining a CPU the architecture may iterate over resources in any order.\nFor example, the MBA control domain may be offlined before or after\na corresponding L3 monitor domain. Ensure that resctrl fs cancels the workers\nno matter what order the architecture offlines the domains."
          }
        ],
        "id": "CVE-2026-93099",
        "lastModified": "2026-10-19T10:16:59.723",
        "metrics": {},
        "published": "2026-09-17T17:18:04.110",
        "references": [
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/2566b5cd6a275c124e8f154fef6e815f92ec8d5c"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/6a2e023429a41afd0d9dfe74268aa51774a953ff"
          },
          {
            "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            "url": "https://git.kernel.org/stable/c/b86dbfe4583bf134932a6cc45bf25b12c10a0b2f"
          }
        ],
        "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "vulnStatus": "Received"
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-10-21T04:37:06+00:00",
      "cve": "CVE-2026-93099",
      "id": "CVE-2026-93099",
      "initial_release_date": "2026-09-17T00:00:00+00:00",
      "product_status:known_affected": "186",
      "product_status:known_not_affected": "91",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: fs/resctrl: Fix UAF from worker threads when domains are removed",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-93099.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-10-20T00:27:44Z",
      "cve": "CVE-2026-93099",
      "id": "CVE-2026-93099",
      "initial_release_date": "2026-09-18T00:12:09Z",
      "product_status:known_affected": "342",
      "product_status:known_not_affected": "6",
      "product_status:recommended": "4",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2026-93099",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/2026/cve-2026-93099.json",
      "version": "7"
    }
  }
}



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.