{"id":"CVE-2026-64364","revision":"b8e566d0d944480f8f023d762ef457fc","records":[{"revision":"b8e566d0d944480f8f023d762ef457fc","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-64364","aliases":[],"title":"HID: multitouch: fix out-of-bounds bit access on mt_io_flags","description":"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_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.","state":0,"publishedAt":"2026-07-25T08:50:19.441+00:00","modifiedAt":"2026-10-19T20:38:24.727+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/hid/hid-multitouch.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"fc488f675344931ffab6a51c43691065ec006567\",\n                            \"lessThan\": \"12e90656e330ff8bbaf2f29c535fdb8a11cc6f55\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"77711d850bed75ae7142c3d1f22c1a8b4d049c33\",\n                            \"lessThan\": \"152983d87387f6a8ae72b73474cfa55fbcf1ec75\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"6acfe25968913788d30ec0eedd80178c4ea3f1d0\",\n                            \"lessThan\": \"b5c037d6b807017e74a115288f81bc9cd5a5aab8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"d280c138e66be87d1fccfed42593f02fdb893905\",\n                            \"lessThan\": \"a6d5ce2e1a2d7bf189bde8a659d04b65f0b0725d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"f32fea4c0234c971c12e46d76612cdc2dd4bb046\",\n                            \"lessThan\": \"e24918ee67c4dc3d20d4670750e46e9b160365f4\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"46f781e0d151844589dc2125c8cce3300546f92a\",\n                            \"lessThan\": \"37daa8c96bd563d03150e23f094cb60703594a6d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"46f781e0d151844589dc2125c8cce3300546f92a\",\n                            \"lessThan\": \"6493ebf9489efef0105078377b973ab33d51af22\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"46f781e0d151844589dc2125c8cce3300546f92a\",\n                            \"lessThan\": \"8813b0612275cc61fe9e6603d0ee019247ade6be\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"59bd04163e6451b9c7275277882ed9f4abfa2051\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"5.10.246\",\n                            \"lessThan\": \"5.10.261\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.196\",\n                            \"lessThan\": \"5.15.212\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.158\",\n                            \"lessThan\": \"6.1.178\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.114\",\n                            \"lessThan\": \"6.6.145\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.55\",\n                            \"lessThan\": \"6.12.97\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.17.5\",\n                            \"lessThan\": \"6.18\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"drivers/hid/hid-multitouch.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.18\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.18\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.261\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.212\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.178\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.145\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.97\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.39\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.4\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","score":8.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/12e90656e330ff8bbaf2f29c535fdb8a11cc6f55","https://git.kernel.org/stable/c/152983d87387f6a8ae72b73474cfa55fbcf1ec75","https://git.kernel.org/stable/c/b5c037d6b807017e74a115288f81bc9cd5a5aab8","https://git.kernel.org/stable/c/a6d5ce2e1a2d7bf189bde8a659d04b65f0b0725d","https://git.kernel.org/stable/c/e24918ee67c4dc3d20d4670750e46e9b160365f4","https://git.kernel.org/stable/c/37daa8c96bd563d03150e23f094cb60703594a6d","https://git.kernel.org/stable/c/6493ebf9489efef0105078377b973ab33d51af22","https://git.kernel.org/stable/c/8813b0612275cc61fe9e6603d0ee019247ade6be"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64364","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-64364","identifiers":["CVE-2026-64364"]},"retained":false,"historicalAffected":[]}],"coverage":[]}