FKIE_CVE-2026-64365

Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-07-25 10:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: HID: letsketch: fix UAF on inrange_timer at driver unbind letsketch_driver does not provide a .remove callback, but letsketch_probe() arms a per-device timer: timer_setup(&data->inrange_timer, letsketch_inrange_timeout, 0); The timer is re-armed from letsketch_raw_event() with a 100 ms timeout on every pen-in-range report, and its callback dereferences data->input_tablet to deliver a synthetic BTN_TOOL_PEN release. letsketch_data is allocated with devm_kzalloc(), and its input_dev fields are devm-allocated via letsketch_setup_input_tablet(). On device unbind (USB unplug or rmmod), the HID core runs its default teardown and devm cleanup frees both letsketch_data and the input devices. Because no .remove callback exists, nothing drains the timer first: if raw_event armed it within ~100 ms of the unbind, the pending timer fires on freed memory. This is a UAF read of data and of data->input_tablet, followed by input_report_key() / input_sync() into the freed input_dev. The same problem can occur on the probe error path: if hid_hw_start() enabled I/O on an always-poll-quirk device and then failed, raw_event may have armed the timer before devm releases data. Fix by adding a .remove callback that calls hid_hw_stop() first. hid_hw_stop() synchronously kills the URBs that deliver raw_event(), so once it returns no path can re-arm the timer. timer_shutdown_sync() then drains any in-flight callback and permanently disables further mod_timer() calls. Apply the same timer_shutdown_sync() in the probe error path so the timer is guaranteed not to outlive data.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/17f5928d7010bc9e002930326b59e60e40c09ee3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/2bb6e7143cf70ed281822d26c1848b2897ac36e9
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3eca1a8165b5e7996e699e9df76cb4645e184d42
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/46c8beeccd8ab2c863827254a85ea877654a3534
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/523db788c0f84612707638e266e8957ca7e3a756
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/df3d8aa1a9392da3de66398e7a03422463806b21
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/hid/hid-letsketch.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "2bb6e7143cf70ed281822d26c1848b2897ac36e9",
              "status": "affected",
              "version": "33a5c2793451770cb6dcf0cc35c76cfd4b045513",
              "versionType": "git"
            },
            {
              "lessThan": "523db788c0f84612707638e266e8957ca7e3a756",
              "status": "affected",
              "version": "33a5c2793451770cb6dcf0cc35c76cfd4b045513",
              "versionType": "git"
            },
            {
              "lessThan": "17f5928d7010bc9e002930326b59e60e40c09ee3",
              "status": "affected",
              "version": "33a5c2793451770cb6dcf0cc35c76cfd4b045513",
              "versionType": "git"
            },
            {
              "lessThan": "3eca1a8165b5e7996e699e9df76cb4645e184d42",
              "status": "affected",
              "version": "33a5c2793451770cb6dcf0cc35c76cfd4b045513",
              "versionType": "git"
            },
            {
              "lessThan": "df3d8aa1a9392da3de66398e7a03422463806b21",
              "status": "affected",
              "version": "33a5c2793451770cb6dcf0cc35c76cfd4b045513",
              "versionType": "git"
            },
            {
              "lessThan": "46c8beeccd8ab2c863827254a85ea877654a3534",
              "status": "affected",
              "version": "33a5c2793451770cb6dcf0cc35c76cfd4b045513",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/hid/hid-letsketch.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.17"
            },
            {
              "lessThan": "5.17",
              "status": "unaffected",
              "version": "0",
              "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": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc3",
              "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\nHID: letsketch: fix UAF on inrange_timer at driver unbind\n\nletsketch_driver does not provide a .remove callback, but\nletsketch_probe() arms a per-device timer:\n\n    timer_setup(\u0026data-\u003einrange_timer, letsketch_inrange_timeout, 0);\n\nThe timer is re-armed from letsketch_raw_event() with a 100 ms\ntimeout on every pen-in-range report, and its callback dereferences\ndata-\u003einput_tablet to deliver a synthetic BTN_TOOL_PEN release.\n\nletsketch_data is allocated with devm_kzalloc(), and its input_dev\nfields are devm-allocated via letsketch_setup_input_tablet().  On\ndevice unbind (USB unplug or rmmod), the HID core runs its default\nteardown and devm cleanup frees both letsketch_data and the input\ndevices.  Because no .remove callback exists, nothing drains the\ntimer first: if raw_event armed it within ~100 ms of the unbind,\nthe pending timer fires on freed memory.  This is a UAF read of\ndata and of data-\u003einput_tablet, followed by input_report_key() /\ninput_sync() into the freed input_dev.\n\nThe same problem can occur on the probe error path: if\nhid_hw_start() enabled I/O on an always-poll-quirk device and then\nfailed, raw_event may have armed the timer before devm releases\ndata.\n\nFix by adding a .remove callback that calls hid_hw_stop() first.\nhid_hw_stop() synchronously kills the URBs that deliver raw_event(),\nso once it returns no path can re-arm the timer.  timer_shutdown_sync()\nthen drains any in-flight callback and permanently disables further\nmod_timer() calls.  Apply the same timer_shutdown_sync() in the probe\nerror path so the timer is guaranteed not to outlive data."
    }
  ],
  "id": "CVE-2026-64365",
  "lastModified": "2026-07-25T10:17:19.280",
  "metrics": {},
  "published": "2026-07-25T10:17:19.280",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/17f5928d7010bc9e002930326b59e60e40c09ee3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/2bb6e7143cf70ed281822d26c1848b2897ac36e9"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/3eca1a8165b5e7996e699e9df76cb4645e184d42"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/46c8beeccd8ab2c863827254a85ea877654a3534"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/523db788c0f84612707638e266e8957ca7e3a756"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/df3d8aa1a9392da3de66398e7a03422463806b21"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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