{"id":"CVE-2026-46213","state":"PUBLISHED","title":"HID: appletb-kbd: fix UAF in inactivity-timer cleanup path","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.","publishedAt":"2026-05-28T09:40:30.429Z","updatedAt":"2026-06-14T18:03:11.677Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"38224c472a038fa9ccd4085511dd9f3d6119dbf9","status":"affected","lessThan":"59a79938ca5541fe55d675304116b7ea684afef0","versionType":"git"},{"version":"38224c472a038fa9ccd4085511dd9f3d6119dbf9","status":"affected","lessThan":"93d989e47bc316c793a69c6a332e053c90e29f02","versionType":"git"},{"version":"38224c472a038fa9ccd4085511dd9f3d6119dbf9","status":"affected","lessThan":"4db2af929279c799b5653a39eb0795c72baffca4","versionType":"git"},{"version":"51720dee3a61ebace36c3dcdd0b4a488e0970f29","status":"affected","versionType":"git"},{"version":"6.15.6","status":"affected","lessThan":"6.16","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hid/hid-appletb-kbd.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.32","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.9","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hid/hid-appletb-kbd.c"]}],"references":["https://git.kernel.org/stable/c/59a79938ca5541fe55d675304116b7ea684afef0","https://git.kernel.org/stable/c/93d989e47bc316c793a69c6a332e053c90e29f02","https://git.kernel.org/stable/c/4db2af929279c799b5653a39eb0795c72baffca4"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/46xxx/CVE-2026-46213.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46213","state":"PUBLISHED","datePublished":"2026-05-28T09:40:30.429Z","dateUpdated":"2026-06-14T18:03:11.677Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-13T15:03:33.105Z"},"containers":{"cna":{"title":"HID: appletb-kbd: fix UAF in inactivity-timer cleanup path","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"38224c472a038fa9ccd4085511dd9f3d6119dbf9","status":"affected","lessThan":"59a79938ca5541fe55d675304116b7ea684afef0","versionType":"git"},{"version":"38224c472a038fa9ccd4085511dd9f3d6119dbf9","status":"affected","lessThan":"93d989e47bc316c793a69c6a332e053c90e29f02","versionType":"git"},{"version":"38224c472a038fa9ccd4085511dd9f3d6119dbf9","status":"affected","lessThan":"4db2af929279c799b5653a39eb0795c72baffca4","versionType":"git"},{"version":"51720dee3a61ebace36c3dcdd0b4a488e0970f29","status":"affected","versionType":"git"},{"version":"6.15.6","status":"affected","lessThan":"6.16","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hid/hid-appletb-kbd.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.16","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.16","versionType":"semver"},{"version":"6.18.32","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.9","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hid/hid-appletb-kbd.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/59a79938ca5541fe55d675304116b7ea684afef0"},{"url":"https://git.kernel.org/stable/c/93d989e47bc316c793a69c6a332e053c90e29f02"},{"url":"https://git.kernel.org/stable/c/4db2af929279c799b5653a39eb0795c72baffca4"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-06-14T18:03:11.677Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"6.18.32"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.0.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.16","versionEndExcluding":"7.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.15.6"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}