{"id":"CVE-2026-98859","title":"HID: multitouch: stop the release timer from being rearmed on remove","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nHID: multitouch: stop the release timer from being rearmed on remove\n\nmt_remove() quiesces the sticky-finger timer before stopping the\nhardware:\n\n    timer_delete_sync(…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 4f4001bc76fd1a138a501fbd3d68cce72cbf96ce < 1f1bd9a3117f082eb891c0986c4f0e04cd974c9a","Linux >= 4f4001bc76fd1a138a501fbd3d68cce72cbf96ce < 0c19a6c1d25fd5ed66d1f80dc6f6e56cc1f0a787","Linux >= 4f4001bc76fd1a138a501fbd3d68cce72cbf96ce < a0125ca86e405b8a704e96157a6c10ca51087652","Linux >= 4f4001bc76fd1a138a501fbd3d68cce72cbf96ce < 5acb2dace582f061aab5e14c399ac9480315f44b","Linux 4.13"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:51:20.456Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98859","references":[{"url":"https://git.kernel.org/stable/c/1f1bd9a3117f082eb891c0986c4f0e04cd974c9a"},{"url":"https://git.kernel.org/stable/c/0c19a6c1d25fd5ed66d1f80dc6f6e56cc1f0a787"},{"url":"https://git.kernel.org/stable/c/a0125ca86e405b8a704e96157a6c10ca51087652"},{"url":"https://git.kernel.org/stable/c/5acb2dace582f061aab5e14c399ac9480315f44b"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T16:47:32.460Z","slug":"CVE-2026-98859","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nHID: multitouch: stop the release timer from being rearmed on remove\n\nmt_remove() quiesces the sticky-finger timer before stopping the\nhardware:\n\n    timer_delete_sync(&td->release_timer);\n\n    sysfs_remove_group(&hdev->dev.kobj, &mt_attribute_group);\n    hid_hw_stop(hdev);\n\ntimer_delete_sync() waits for a running callback and dequeues the timer,\nbut it does not stop the timer from being armed again. The transport is\nstill delivering reports at that point, and the report path rearms it:\n\n    if (app->quirks & MT_QUIRK_STICKY_FINGERS) {\n        if (td->mt_io_flags & MT_IO_SLOTS_MASK)\n            mod_timer(&td->release_timer,\n                      jiffies + msecs_to_jiffies(100));\n\nA report that arrives after timer_delete_sync() has returned therefore\nleaves the timer queued. td is allocated with devm_kzalloc() against\nhdev->dev, so it is freed when the driver is unbound, after mt_remove()\nreturns. When the timer fires afterwards, mt_expired_timeout()\ndereferences the freed td:\n\n    struct mt_device *td = timer_container_of(td, t, release_timer);\n    struct hid_device *hdev = td->hdev;\n\n    if (test_and_set_bit_lock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags))\n\nSimply moving the teardown after hid_hw_stop() does not fix this on its\nown, because mt_expired_timeout() calls mt_release_contacts(), which\nwalks hdev->inputs; the timer still has to be quiesced before\nhid_hw_stop() tears the input devices down.\n\nUse timer_shutdown_sync() instead, which additionally makes any later\nmod_timer() a no-op, so neither ordering constraint has to be traded off\nagainst the other. This is the final-teardown pattern the function was\nintroduced for, and hid-wiimote already uses it for the same reason.\n\n## Affected\n\n- `Linux >= 4f4001bc76fd1a138a501fbd3d68cce72cbf96ce < 1f1bd9a3117f082eb891c0986c4f0e04cd974c9a`\n- `Linux >= 4f4001bc76fd1a138a501fbd3d68cce72cbf96ce < 0c19a6c1d25fd5ed66d1f80dc6f6e56cc1f0a787`\n- `Linux >= 4f4001bc76fd1a138a501fbd3d68cce72cbf96ce < a0125ca86e405b8a704e96157a6c10ca51087652`\n- `Linux >= 4f4001bc76fd1a138a501fbd3d68cce72cbf96ce < 5acb2dace582f061aab5e14c399ac9480315f44b`\n- `Linux 4.13`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}