{"cve":"CVE-2026-46213","nvd":{"published":"2026-05-28T10:16:36.947","modified":"2026-06-17T10:53:19.853","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nHID: appletb-kbd: fix UAF in inactivity-timer cleanup path\n\nCommit 38224c472a03 (\"HID: appletb-kbd: fix slab use-after-free bug in\nappletb_kbd_probe\") added timer_delete_sync(&kbd->inactivity_timer) to\nboth the probe close_hw error path and appletb_kbd_remove(), but the\nway it was wired in left the inactivity timer reachable during driver\ntear-down via two distinct windows.\n\nWindow A -- put_device() before timer_delete_sync():\n\n\tput_device(&kbd->backlight_dev->dev);\n\ttimer_delete_sync(&kbd->inactivity_timer);\n\nThe inactivity_timer softirq reads kbd->backlight_dev and calls\nbacklight_device_set_brightness() -> mutex_lock(&ops_lock).  If a\nconcurrent hid_appletb_bl unbind drops the last devm reference\nbetween these two calls, the backlight_device is freed and the\nmutex_lock() touches freed memory.\n\nWindow B -- backlight cleanup before hid_hw_stop():\n\n\tif (kbd->backlight_dev) {\n\t\ttimer_delete_sync(...);\n\t\tput_device(...);\n\t}\n\thid_hw_close(hdev);\n\thid_hw_stop(hdev);\n\nEven after Window A is closed, hid_hw_close()/hid_hw_stop() still run\nafterwards, so a late \".event\" callback from the HID core (USB URB\ncompletion on real Apple hardware) can arrive after\ntimer_delete_sync() drained the softirq but before put_device() drops\nthe reference.  That callback reaches reset_inactivity_timer(), which\ncalls mod_timer() and re-arms the timer.  The freshly re-armed timer\ncan then fire on the about-to-be-freed backlight_device.\n\nBoth windows produce the same KASAN slab-use-after-free:\n\n  BUG: KASAN: slab-use-after-free in __mutex_lock+0x1aab/0x21c0\n  Read of size 8 at addr ffff88803ee9a108 by task swapper/0/0\n  Call Trace:\n   <IRQ>\n   __mutex_lock\n   backlight_device_set_brightness\n   appletb_inactivity_timer\n   call_timer_fn\n   run_timer_softirq\n   handle_softirqs\n  Allocated by task N:\n   devm_backlight_device_register\n   appletb_bl_probe\n  Freed by task M:\n   (concurrent hid_appletb_bl unbind path)\n\nClose both windows at once by reworking the tear-down in\nappletb_kbd_remove() and in the probe close_hw error path so that\n\n 1) hid_hw_close()/hid_hw_stop() run before the backlight cleanup,\n    guaranteeing no further .event callback can fire and re-arm the\n    timer, and\n 2) inside the \"if (kbd->backlight_dev)\" block, timer_delete_sync()\n    runs before put_device(), so the softirq is drained before the\n    final reference is dropped.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/4db2af929279c799b5653a39eb0795c72baffca4","https://git.kernel.org/stable/c/59a79938ca5541fe55d675304116b7ea684afef0","https://git.kernel.org/stable/c/93d989e47bc316c793a69c6a332e053c90e29f02"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:36:28.938604137+00:00"},"epss":{"cve":"CVE-2026-46213","score":0.00124,"percentile":0.0209,"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."]}