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GHSA-W4G4-GF2V-88RM

Vulnerability from github – Published: 2026-05-28 12:30 – Updated: 2026-05-28 12:30

Details

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

HID: appletb-kbd: run inactivity autodim from workqueues

The autodim code in hid-appletb-kbd takes backlight_device->ops_lock via backlight_device_set_brightness() -> mutex_lock() from two different atomic contexts:

appletb_inactivity_timer() is a struct timer_list callback, so it runs in softirq context. Every expiry triggers

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591 Call Trace: __might_resched __mutex_lock backlight_device_set_brightness appletb_inactivity_timer call_timer_fn run_timer_softirq
reset_inactivity_timer() is called from appletb_kbd_hid_event() and appletb_kbd_inp_event(). On real USB hardware these run in softirq/IRQ context (URB completion and input-event dispatch). When the Touch Bar has already been dimmed or turned off, the reset path calls backlight_device_set_brightness() directly to restore brightness, producing the same warning.

Both call sites hit the same mutex_lock()-from-atomic bug. Fix them together by moving the blocking work onto the system workqueue:

Convert the inactivity timer from struct timer_list to struct delayed_work; the callback (appletb_inactivity_work) now runs in process context where mutex_lock() is legal.
Add a dedicated struct work_struct restore_brightness_work and have reset_inactivity_timer() schedule it instead of calling backlight_device_set_brightness() directly.

Cancel both works synchronously during driver tear-down alongside the existing backlight reference drop.

The semantics are unchanged (same delays, same state transitions on dim, turn-off and user activity); only the execution context of the sleeping call changes. The timer field and callback are renamed to match their new type; reset_inactivity_timer() keeps its name because it is invoked from input event paths that read naturally as "reset the inactivity timer".

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{
  "affected": [],
  "aliases": [
    "CVE-2026-46202"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-28T10:16:35Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nHID: appletb-kbd: run inactivity autodim from workqueues\n\nThe autodim code in hid-appletb-kbd takes backlight_device-\u003eops_lock\nvia backlight_device_set_brightness() -\u003e mutex_lock() from two\ndifferent atomic contexts:\n\n * appletb_inactivity_timer() is a struct timer_list callback, so it\n   runs in softirq context.  Every expiry triggers\n\n     BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591\n     Call Trace:\n      \u003cIRQ\u003e\n      __might_resched\n      __mutex_lock\n      backlight_device_set_brightness\n      appletb_inactivity_timer\n      call_timer_fn\n      run_timer_softirq\n\n * reset_inactivity_timer() is called from appletb_kbd_hid_event() and\n   appletb_kbd_inp_event().  On real USB hardware these run in\n   softirq/IRQ context (URB completion and input-event dispatch).\n   When the Touch Bar has already been dimmed or turned off, the\n   reset path calls backlight_device_set_brightness() directly to\n   restore brightness, producing the same warning.\n\nBoth call sites hit the same mutex_lock()-from-atomic bug.  Fix them\ntogether by moving the blocking work onto the system workqueue:\n\n * Convert the inactivity timer from struct timer_list to\n   struct delayed_work; the callback (appletb_inactivity_work) now\n   runs in process context where mutex_lock() is legal.\n * Add a dedicated struct work_struct restore_brightness_work and have\n   reset_inactivity_timer() schedule it instead of calling\n   backlight_device_set_brightness() directly.\n\nCancel both works synchronously during driver tear-down alongside the\nexisting backlight reference drop.\n\nThe semantics are unchanged (same delays, same state transitions on\ndim, turn-off and user activity); only the execution context of the\nsleeping call changes.  The timer field and callback are renamed to\nmatch their new type; reset_inactivity_timer() keeps its name because\nit is invoked from input event paths that read naturally as \"reset\nthe inactivity timer\".",
  "id": "GHSA-w4g4-gf2v-88rm",
  "modified": "2026-05-28T12:30:33Z",
  "published": "2026-05-28T12:30:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-46202"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1654e53349d4e657b331de354313461f401f5063"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2473a334c292af257ef68e33bc7760f4a8251812"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5c0830323689ef15224f0025276176988861b3b0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-46202 (GCVE-0-2026-46202)

Vulnerability from cvelistv5 – Published: 2026-05-28 09:40 – Updated: 2026-05-28 09:40

Title

HID: appletb-kbd: run inactivity autodim from workqueues

Summary

In the Linux kernel, the following vulnerability has been resolved: HID: appletb-kbd: run inactivity autodim from workqueues The autodim code in hid-appletb-kbd takes backlight_device->ops_lock via backlight_device_set_brightness() -> mutex_lock() from two different atomic contexts: * appletb_inactivity_timer() is a struct timer_list callback, so it runs in softirq context. Every expiry triggers BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591 Call Trace: <IRQ> __might_resched __mutex_lock backlight_device_set_brightness appletb_inactivity_timer call_timer_fn run_timer_softirq * reset_inactivity_timer() is called from appletb_kbd_hid_event() and appletb_kbd_inp_event(). On real USB hardware these run in softirq/IRQ context (URB completion and input-event dispatch). When the Touch Bar has already been dimmed or turned off, the reset path calls backlight_device_set_brightness() directly to restore brightness, producing the same warning. Both call sites hit the same mutex_lock()-from-atomic bug. Fix them together by moving the blocking work onto the system workqueue: * Convert the inactivity timer from struct timer_list to struct delayed_work; the callback (appletb_inactivity_work) now runs in process context where mutex_lock() is legal. * Add a dedicated struct work_struct restore_brightness_work and have reset_inactivity_timer() schedule it instead of calling backlight_device_set_brightness() directly. Cancel both works synchronously during driver tear-down alongside the existing backlight reference drop. The semantics are unchanged (same delays, same state transitions on dim, turn-off and user activity); only the execution context of the sleeping call changes. The timer field and callback are renamed to match their new type; reset_inactivity_timer() keeps its name because it is invoked from input event paths that read naturally as "reset the inactivity timer".

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/5c0830323689ef152…
https://git.kernel.org/stable/c/2473a334c292af257…
https://git.kernel.org/stable/c/1654e53349d4e657b…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 93a0fc48948107e0cc34e1de22c3cb363a8f2783 , < 5c0830323689ef15224f0025276176988861b3b0 (git) Affected: 93a0fc48948107e0cc34e1de22c3cb363a8f2783 , < 2473a334c292af257ef68e33bc7760f4a8251812 (git) Affected: 93a0fc48948107e0cc34e1de22c3cb363a8f2783 , < 1654e53349d4e657b331de354313461f401f5063 (git)
Linux	Linux	Affected: 6.15 Unaffected: 0 , < 6.15 (semver) Unaffected: 6.18.32 , ≤ 6.18.* (semver) Unaffected: 7.0.9 , ≤ 7.0.* (semver) Unaffected: 7.1-rc4 , ≤ * (original_commit_for_fix)

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{
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        {
          "defaultStatus": "unaffected",
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          "programFiles": [
            "drivers/hid/hid-appletb-kbd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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          "versions": [
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              "status": "affected",
              "version": "93a0fc48948107e0cc34e1de22c3cb363a8f2783",
              "versionType": "git"
            },
            {
              "lessThan": "2473a334c292af257ef68e33bc7760f4a8251812",
              "status": "affected",
              "version": "93a0fc48948107e0cc34e1de22c3cb363a8f2783",
              "versionType": "git"
            },
            {
              "lessThan": "1654e53349d4e657b331de354313461f401f5063",
              "status": "affected",
              "version": "93a0fc48948107e0cc34e1de22c3cb363a8f2783",
              "versionType": "git"
            }
          ]
        },
        {
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          "product": "Linux",
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            "drivers/hid/hid-appletb-kbd.c"
          ],
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          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.15"
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              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
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            {
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              "status": "unaffected",
              "version": "6.18.32",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.9",
              "versionType": "semver"
            },
            {
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              "status": "unaffected",
              "version": "7.1-rc4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.32",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.9",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1-rc4",
                  "versionStartIncluding": "6.15",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nHID: appletb-kbd: run inactivity autodim from workqueues\n\nThe autodim code in hid-appletb-kbd takes backlight_device-\u003eops_lock\nvia backlight_device_set_brightness() -\u003e mutex_lock() from two\ndifferent atomic contexts:\n\n * appletb_inactivity_timer() is a struct timer_list callback, so it\n   runs in softirq context.  Every expiry triggers\n\n     BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591\n     Call Trace:\n      \u003cIRQ\u003e\n      __might_resched\n      __mutex_lock\n      backlight_device_set_brightness\n      appletb_inactivity_timer\n      call_timer_fn\n      run_timer_softirq\n\n * reset_inactivity_timer() is called from appletb_kbd_hid_event() and\n   appletb_kbd_inp_event().  On real USB hardware these run in\n   softirq/IRQ context (URB completion and input-event dispatch).\n   When the Touch Bar has already been dimmed or turned off, the\n   reset path calls backlight_device_set_brightness() directly to\n   restore brightness, producing the same warning.\n\nBoth call sites hit the same mutex_lock()-from-atomic bug.  Fix them\ntogether by moving the blocking work onto the system workqueue:\n\n * Convert the inactivity timer from struct timer_list to\n   struct delayed_work; the callback (appletb_inactivity_work) now\n   runs in process context where mutex_lock() is legal.\n * Add a dedicated struct work_struct restore_brightness_work and have\n   reset_inactivity_timer() schedule it instead of calling\n   backlight_device_set_brightness() directly.\n\nCancel both works synchronously during driver tear-down alongside the\nexisting backlight reference drop.\n\nThe semantics are unchanged (same delays, same state transitions on\ndim, turn-off and user activity); only the execution context of the\nsleeping call changes.  The timer field and callback are renamed to\nmatch their new type; reset_inactivity_timer() keeps its name because\nit is invoked from input event paths that read naturally as \"reset\nthe inactivity timer\"."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-28T09:40:18.687Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/5c0830323689ef15224f0025276176988861b3b0"
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          "url": "https://git.kernel.org/stable/c/2473a334c292af257ef68e33bc7760f4a8251812"
        },
        {
          "url": "https://git.kernel.org/stable/c/1654e53349d4e657b331de354313461f401f5063"
        }
      ],
      "title": "HID: appletb-kbd: run inactivity autodim from workqueues",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-46202",
    "datePublished": "2026-05-28T09:40:18.687Z",
    "dateReserved": "2026-05-13T15:03:33.104Z",
    "dateUpdated": "2026-05-28T09:40:18.687Z",
    "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.

Action not permitted

GHSA-W4G4-GF2V-88RM

CVE-2026-46202 (GCVE-0-2026-46202)

Tags

Sightings

Nomenclature