{"id":"CVE-2026-64364","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nHID: multitouch: fix out-of-bounds bit access on mt_io_flags\n\nmt_io_flags is a single unsigned long, but mt_process_slot(),\nmt_release_pending_palms() and mt_release_co…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nHID: multitouch: fix out-of-bounds bit access on mt_io_flags\n\nmt_io_flags is a single unsigned long, but mt_process_slot(),\nmt_release_pending_palms() and mt_release_co…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-125"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.10.246, < 5.10.261","linux_kernel >= 5.15.196, < 5.15.212","linux_kernel >= 6.1.158, < 6.1.178","linux_kernel >= 6.6.114, < 6.6.145","linux_kernel >= 6.12.55, < 6.12.97","linux_kernel >= 6.17.5, < 6.18","linux_kernel >= 6.18.1, < 6.18.39","linux_kernel >= 6.19, < 7.1.4","linux_kernel = 6.18","linux_kernel = 7.2"],"patched":["linux_kernel 7.1.4"],"published":"2026-07-25","updated":"2026-09-10","sourceUpdated":"2026-09-10T21:35:45.760","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64364","references":[{"url":"https://git.kernel.org/stable/c/12e90656e330ff8bbaf2f29c535fdb8a11cc6f55","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/152983d87387f6a8ae72b73474cfa55fbcf1ec75","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/37daa8c96bd563d03150e23f094cb60703594a6d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6493ebf9489efef0105078377b973ab33d51af22","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8813b0612275cc61fe9e6603d0ee019247ade6be","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a6d5ce2e1a2d7bf189bde8a659d04b65f0b0725d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b5c037d6b807017e74a115288f81bc9cd5a5aab8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e24918ee67c4dc3d20d4670750e46e9b160365f4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00354,"epssPercentile":0.26373,"ingestedAt":"2026-07-27T06:16:50.734Z","slug":"CVE-2026-64364","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nHID: multitouch: fix out-of-bounds bit access on mt_io_flags\n\nmt_io_flags is a single unsigned long, but mt_process_slot(),\nmt_release_pending_palms() and mt_release_contacts() use it as a\nper-slot bitmap indexed by the slot number. That slot number is only\nbounded by td->maxcontacts, which is taken from the device's\nContactCountMaximum feature report and can be up to 255, not by\nBITS_PER_LONG.\n\nAs a result, a multitouch device that advertises a large contact count\nmakes set_bit()/clear_bit() operate past the mt_io_flags word and\ncorrupt the adjacent members of struct mt_device. The sticky-fingers\nrelease timer is the easiest way to reach this. mt_release_contacts()\nruns\n\n\tfor (i = 0; i < mt->num_slots; i++)\n\t\tclear_bit(i, &td->mt_io_flags);\n\nwith num_slots == maxcontacts. For maxcontacts around 250 the loop\nclears the bits that overlap td->applications.next, zeroing that list\nhead, and the list_for_each_entry() that immediately follows then\ndereferences NULL. The kernel panics from timer (softirq) context. On a\nKASAN build this shows up as a general protection fault in\nmt_release_contacts() with a null-ptr-deref at offset 0x58, which is\noffsetof(struct mt_application, num_received).\n\nThe state is reachable from an untrusted USB or Bluetooth HID\nmultitouch device; no local privileges are required.\n\nStore the per-slot active state in a separately allocated bitmap sized\nfor maxcontacts, the same pattern already used for pending_palm_slots,\nand keep only MT_IO_FLAGS_RUNNING in mt_io_flags. The two\n\"mt_io_flags & MT_IO_SLOTS_MASK\" arming checks become\nbitmap_empty(td->active_slots, td->maxcontacts).\n\nMove MT_IO_FLAGS_RUNNING back to bit 0. It was bumped to bit 32 by the\nsame commit to leave the low byte for the slot bits; with the slot bits\ngone it fits in bit 0 again, which also keeps it within the unsigned\nlong on 32-bit.\n\n## Affected\n\n- `linux_kernel >= 5.10.246, < 5.10.261`\n- `linux_kernel >= 5.15.196, < 5.15.212`\n- `linux_kernel >= 6.1.158, < 6.1.178`\n- `linux_kernel >= 6.6.114, < 6.6.145`\n- `linux_kernel >= 6.12.55, < 6.12.97`\n- `linux_kernel >= 6.17.5, < 6.18`\n- `linux_kernel >= 6.18.1, < 6.18.39`\n- `linux_kernel >= 6.19, < 7.1.4`\n- `linux_kernel = 6.18`\n- `linux_kernel = 7.2`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.1.4`","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}