{"id":"CVE-2026-46213","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-46213","generatedAt":"2026-10-28T04:35:32.219Z","title":"In the Linux kernel, the following vulnerability has been resolved: HID: appletb-kbd: fix UAF in inactivity-timer cleanup path Commit 38224c472a03 (\"HID: appletb-kbd: fix slab use-after-free bug in appletb_kbd_probe\") added…","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.","published":"2026-05-28T10:16:37.000Z","lastModified":"2026-06-17T10:53:20.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.8,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-416"],"affected":["linux/linux kernel"],"epss":{"score":0.00124,"percentile":0.02097,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.12%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/4db2af929279c799b5653a39eb0795c72baffca4","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/59a79938ca5541fe55d675304116b7ea684afef0","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/93d989e47bc316c793a69c6a332e053c90e29f02","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-46213","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}