CVE-2026-80622 (GCVE-0-2026-80622)

Vulnerability from cvelistv5 – Published: 2026-08-28 06:48 – Updated: 2026-08-29 06:21
VLAI
Title
char: tlclk: fix use-after-free in tlclk_cleanup()
Summary
In the Linux kernel, the following vulnerability has been resolved: char: tlclk: fix use-after-free in tlclk_cleanup() This patch improves the module cleanup process in the tlclk driver to prevent potential use-after-free and race conditions. Currently, the file_operations structure does not specify the .owner field, which could allow the module to be unloaded while user-space processes are still interacting with the device. Additionally, the tlclk_cleanup() function frees the alarm_events memory before ensuring that blocked processes in the waitqueue are fully awakened and that the switchover_timer has completed. To address these cases, this patch: - Sets '.owner = THIS_MODULE' in tlclk_fops to safely defer module unloading while the device is in use. - Updates tlclk_cleanup() to explicitly wake up all blocked readers (wake_up_all), properly release hardware I/O regions, and safely delete the timer (timer_delete_sync) prior to freeing memory.
Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 1a80ba88273097933f93b1f40537337416798c70 , < 09d8d2a46a9ec9ff728f3159a174a2ab25dd0f0a (git)
Affected: 1a80ba88273097933f93b1f40537337416798c70 , < 96902299a22d126ef5eb3f45cd5d8ceea9e6a735 (git)
Affected: 1a80ba88273097933f93b1f40537337416798c70 , < 166dd1d5265e067459e674c11688919901813ec2 (git)
Affected: 1a80ba88273097933f93b1f40537337416798c70 , < 764723bd67a6c8f53a8d8309211fb039e2ebcf49 (git)
Affected: 1a80ba88273097933f93b1f40537337416798c70 , < c3f0cd76561ae611c2d247ee96dfd559e4197cb7 (git)
Affected: 1a80ba88273097933f93b1f40537337416798c70 , < 3d5e4cc0d9dce79b0429da3134ac7b072ab9009f (git)
Affected: 1a80ba88273097933f93b1f40537337416798c70 , < 42223445607a9a5df3cb1c4729abfe3a5085e7ce (git)
Affected: 1a80ba88273097933f93b1f40537337416798c70 , < bbf003b7794d6ad6f939fdd29f1f1bde8ac554c1 (git)
guessed Create a notification for this product.
Linux Linux Affected: 2.6.15
Unaffected: 0 , < 2.6.15 (semver)
Unaffected: 5.10.261 , ≤ 5.10.* (semver)
Unaffected: 5.15.212 , ≤ 5.15.* (semver)
Unaffected: 6.1.178 , ≤ 6.1.* (semver)
Unaffected: 6.6.145 , ≤ 6.6.* (semver)
Unaffected: 6.12.97 , ≤ 6.12.* (semver)
Unaffected: 6.18.40 , ≤ 6.18.* (semver)
Unaffected: 7.1.5 , ≤ 7.1.* (semver)
Unaffected: 7.2 , ≤ * (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": [
            "drivers/char/tlclk.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "09d8d2a46a9ec9ff728f3159a174a2ab25dd0f0a",
              "status": "affected",
              "version": "1a80ba88273097933f93b1f40537337416798c70",
              "versionType": "git"
            },
            {
              "lessThan": "96902299a22d126ef5eb3f45cd5d8ceea9e6a735",
              "status": "affected",
              "version": "1a80ba88273097933f93b1f40537337416798c70",
              "versionType": "git"
            },
            {
              "lessThan": "166dd1d5265e067459e674c11688919901813ec2",
              "status": "affected",
              "version": "1a80ba88273097933f93b1f40537337416798c70",
              "versionType": "git"
            },
            {
              "lessThan": "764723bd67a6c8f53a8d8309211fb039e2ebcf49",
              "status": "affected",
              "version": "1a80ba88273097933f93b1f40537337416798c70",
              "versionType": "git"
            },
            {
              "lessThan": "c3f0cd76561ae611c2d247ee96dfd559e4197cb7",
              "status": "affected",
              "version": "1a80ba88273097933f93b1f40537337416798c70",
              "versionType": "git"
            },
            {
              "lessThan": "3d5e4cc0d9dce79b0429da3134ac7b072ab9009f",
              "status": "affected",
              "version": "1a80ba88273097933f93b1f40537337416798c70",
              "versionType": "git"
            },
            {
              "lessThan": "42223445607a9a5df3cb1c4729abfe3a5085e7ce",
              "status": "affected",
              "version": "1a80ba88273097933f93b1f40537337416798c70",
              "versionType": "git"
            },
            {
              "lessThan": "bbf003b7794d6ad6f939fdd29f1f1bde8ac554c1",
              "status": "affected",
              "version": "1a80ba88273097933f93b1f40537337416798c70",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/char/tlclk.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.15"
            },
            {
              "lessThan": "2.6.15",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "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": "5.10.261",
                  "versionStartIncluding": "2.6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.212",
                  "versionStartIncluding": "2.6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.178",
                  "versionStartIncluding": "2.6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6.145",
                  "versionStartIncluding": "2.6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.97",
                  "versionStartIncluding": "2.6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.40",
                  "versionStartIncluding": "2.6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.5",
                  "versionStartIncluding": "2.6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2",
                  "versionStartIncluding": "2.6.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nchar: tlclk: fix use-after-free in tlclk_cleanup()\n\nThis patch improves the module cleanup process in the tlclk driver to\nprevent potential use-after-free and race conditions.\n\nCurrently, the file_operations structure does not specify the .owner\nfield, which could allow the module to be unloaded while user-space\nprocesses are still interacting with the device. Additionally, the\ntlclk_cleanup() function frees the alarm_events memory before ensuring\nthat blocked processes in the waitqueue are fully awakened and that the\nswitchover_timer has completed.\n\nTo address these cases, this patch:\n- Sets \u0027.owner = THIS_MODULE\u0027 in tlclk_fops to safely defer module\n  unloading while the device is in use.\n- Updates tlclk_cleanup() to explicitly wake up all blocked readers\n  (wake_up_all), properly release hardware I/O regions, and safely\n  delete the timer (timer_delete_sync) prior to freeing memory."
        }
      ],
      "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 UAF is reached only via local open/read syscalls on /dev/telco_clock and tlclk_cleanup() during delete_module/rmmod; this x86 ATCA telecom-clock char driver has no network, Bluetooth, or physical-bus attack surface.\nAC:L - Without .owner the attacker controls both sides of the race by keeping /dev/telco_clock open with read() blocked on wq while IRQs remain active, then timing or piggybacking on module unload to hit kfree(alarm_events) against tlclk_read, tlclk_interrupt, or switchover_timeout.\nPR:L - An unprivileged local user with /dev/telco_clock access can open the device and block in read() while IRQs stay registered; per CNA driver-removal UAF precedent, concurrent admin rmmod triggering tlclk_cleanup() does not require the attacker to hold CAP_SYS_MODULE.\nUI:N - No victim interaction is required; the attacker opens /dev/telco_clock and blocks on read() or sustains IRQ/timer activity themselves while module unload occurs during maintenance or coordinated rmmod, without needing another user to act.\nS:U - Kernel heap UAF during tlclk module cleanup affects only the host kernel on the ATCA blade; this is standard in-kernel memory corruption, not a VM escape, IOMMU bypass, or cross-authority sandbox breakout.\nC:H - tlclk_read() performs copy_to_user from freed alarm_events, and tlclk_interrupt/switchover_timeout dereference the freed buffer; this kernel heap UAF enables arbitrary read primitives via controlled slab reuse and information disclosure.\nI:H - tlclk_read() memset() on freed alarm_events and IRQ/timer handlers increment fields in the freed structure, providing kernel heap write primitives exploitable for control-flow hijack via slab spraying and UAF exploitation.\nA:H - Concurrent access to freed alarm_events from read(), switchover_timeout, or tlclk_interrupt during module unload can cause kernel oops/panic; UAF during driver teardown reliably threatens system availability even when not fully weaponized."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-29T06:21:27.766Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/09d8d2a46a9ec9ff728f3159a174a2ab25dd0f0a"
        },
        {
          "url": "https://git.kernel.org/stable/c/96902299a22d126ef5eb3f45cd5d8ceea9e6a735"
        },
        {
          "url": "https://git.kernel.org/stable/c/166dd1d5265e067459e674c11688919901813ec2"
        },
        {
          "url": "https://git.kernel.org/stable/c/764723bd67a6c8f53a8d8309211fb039e2ebcf49"
        },
        {
          "url": "https://git.kernel.org/stable/c/c3f0cd76561ae611c2d247ee96dfd559e4197cb7"
        },
        {
          "url": "https://git.kernel.org/stable/c/3d5e4cc0d9dce79b0429da3134ac7b072ab9009f"
        },
        {
          "url": "https://git.kernel.org/stable/c/42223445607a9a5df3cb1c4729abfe3a5085e7ce"
        },
        {
          "url": "https://git.kernel.org/stable/c/bbf003b7794d6ad6f939fdd29f1f1bde8ac554c1"
        }
      ],
      "title": "char: tlclk: fix use-after-free in tlclk_cleanup()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-80622",
    "datePublished": "2026-08-28T06:48:41.744Z",
    "dateReserved": "2026-08-26T14:34:25.775Z",
    "dateUpdated": "2026-08-29T06:21:27.766Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-80622",
      "date": "2026-09-01",
      "epss": "0.00125",
      "percentile": "0.02512"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-80622\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-28T08:16:46.320\",\"lastModified\":\"2026-08-29T07:16:46.743\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nchar: tlclk: fix use-after-free in tlclk_cleanup()\\n\\nThis patch improves the module cleanup process in the tlclk driver to\\nprevent potential use-after-free and race conditions.\\n\\nCurrently, the file_operations structure does not specify the .owner\\nfield, which could allow the module to be unloaded while user-space\\nprocesses are still interacting with the device. Additionally, the\\ntlclk_cleanup() function frees the alarm_events memory before ensuring\\nthat blocked processes in the waitqueue are fully awakened and that the\\nswitchover_timer has completed.\\n\\nTo address these cases, this patch:\\n- Sets \u0027.owner = THIS_MODULE\u0027 in tlclk_fops to safely defer module\\n  unloading while the device is in use.\\n- Updates tlclk_cleanup() to explicitly wake up all blocked readers\\n  (wake_up_all), properly release hardware I/O regions, and safely\\n  delete the timer (timer_delete_sync) prior to freeing memory.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/char/tlclk.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"1a80ba88273097933f93b1f40537337416798c70\",\"lessThan\":\"09d8d2a46a9ec9ff728f3159a174a2ab25dd0f0a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1a80ba88273097933f93b1f40537337416798c70\",\"lessThan\":\"96902299a22d126ef5eb3f45cd5d8ceea9e6a735\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1a80ba88273097933f93b1f40537337416798c70\",\"lessThan\":\"166dd1d5265e067459e674c11688919901813ec2\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1a80ba88273097933f93b1f40537337416798c70\",\"lessThan\":\"764723bd67a6c8f53a8d8309211fb039e2ebcf49\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1a80ba88273097933f93b1f40537337416798c70\",\"lessThan\":\"c3f0cd76561ae611c2d247ee96dfd559e4197cb7\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1a80ba88273097933f93b1f40537337416798c70\",\"lessThan\":\"3d5e4cc0d9dce79b0429da3134ac7b072ab9009f\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1a80ba88273097933f93b1f40537337416798c70\",\"lessThan\":\"42223445607a9a5df3cb1c4729abfe3a5085e7ce\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"1a80ba88273097933f93b1f40537337416798c70\",\"lessThan\":\"bbf003b7794d6ad6f939fdd29f1f1bde8ac554c1\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/char/tlclk.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"2.6.15\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"2.6.15\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.10.261\",\"lessThanOrEqual\":\"5.10.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"5.15.212\",\"lessThanOrEqual\":\"5.15.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.178\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.6.145\",\"lessThanOrEqual\":\"6.6.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.12.97\",\"lessThanOrEqual\":\"6.12.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.18.40\",\"lessThanOrEqual\":\"6.18.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.1.5\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/09d8d2a46a9ec9ff728f3159a174a2ab25dd0f0a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/166dd1d5265e067459e674c11688919901813ec2\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/3d5e4cc0d9dce79b0429da3134ac7b072ab9009f\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/42223445607a9a5df3cb1c4729abfe3a5085e7ce\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/764723bd67a6c8f53a8d8309211fb039e2ebcf49\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/96902299a22d126ef5eb3f45cd5d8ceea9e6a735\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/bbf003b7794d6ad6f939fdd29f1f1bde8ac554c1\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c3f0cd76561ae611c2d247ee96dfd559e4197cb7\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-31T14:12:44+00:00",
      "cve": "CVE-2026-80622",
      "id": "CVE-2026-80622",
      "initial_release_date": "2026-08-28T00:00:00+00:00",
      "product_status:known_affected": "274",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: char: tlclk: fix use-after-free in tlclk_cleanup()",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80622.json",
      "version": "3"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





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.


Detection rules are retrieved from Rulezet.