{"cve":"CVE-2026-46202","nvd":{"published":"2026-05-28T10:16:35.860","modified":"2026-06-17T10:53:16.110","status":"Analyzed","description":"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->ops_lock\nvia backlight_device_set_brightness() -> 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      <IRQ>\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\".","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/1654e53349d4e657b331de354313461f401f5063","https://git.kernel.org/stable/c/2473a334c292af257ef68e33bc7760f4a8251812","https://git.kernel.org/stable/c/5c0830323689ef15224f0025276176988861b3b0"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:36:28.938604137+00:00"},"epss":{"cve":"CVE-2026-46202","score":0.00128,"percentile":0.02448,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}