FKIE_CVE-2026-64364

Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-07-27 05:16
Severity
8.8 (High) - CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: HID: multitouch: fix out-of-bounds bit access on mt_io_flags mt_io_flags is a single unsigned long, but mt_process_slot(), mt_release_pending_palms() and mt_release_contacts() use it as a per-slot bitmap indexed by the slot number. That slot number is only bounded by td->maxcontacts, which is taken from the device's ContactCountMaximum feature report and can be up to 255, not by BITS_PER_LONG. As a result, a multitouch device that advertises a large contact count makes set_bit()/clear_bit() operate past the mt_io_flags word and corrupt the adjacent members of struct mt_device. The sticky-fingers release timer is the easiest way to reach this. mt_release_contacts() runs for (i = 0; i < mt->num_slots; i++) clear_bit(i, &td->mt_io_flags); with num_slots == maxcontacts. For maxcontacts around 250 the loop clears the bits that overlap td->applications.next, zeroing that list head, and the list_for_each_entry() that immediately follows then dereferences NULL. The kernel panics from timer (softirq) context. On a KASAN build this shows up as a general protection fault in mt_release_contacts() with a null-ptr-deref at offset 0x58, which is offsetof(struct mt_application, num_received). The state is reachable from an untrusted USB or Bluetooth HID multitouch device; no local privileges are required. Store the per-slot active state in a separately allocated bitmap sized for maxcontacts, the same pattern already used for pending_palm_slots, and keep only MT_IO_FLAGS_RUNNING in mt_io_flags. The two "mt_io_flags & MT_IO_SLOTS_MASK" arming checks become bitmap_empty(td->active_slots, td->maxcontacts). Move MT_IO_FLAGS_RUNNING back to bit 0. It was bumped to bit 32 by the same commit to leave the low byte for the slot bits; with the slot bits gone it fits in bit 0 again, which also keeps it within the unsigned long on 32-bit.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/12e90656e330ff8bbaf2f29c535fdb8a11cc6f55
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/152983d87387f6a8ae72b73474cfa55fbcf1ec75
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/37daa8c96bd563d03150e23f094cb60703594a6d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6493ebf9489efef0105078377b973ab33d51af22
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/8813b0612275cc61fe9e6603d0ee019247ade6be
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a6d5ce2e1a2d7bf189bde8a659d04b65f0b0725d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b5c037d6b807017e74a115288f81bc9cd5a5aab8
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e24918ee67c4dc3d20d4670750e46e9b160365f4
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/hid/hid-multitouch.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "12e90656e330ff8bbaf2f29c535fdb8a11cc6f55",
              "status": "affected",
              "version": "fc488f675344931ffab6a51c43691065ec006567",
              "versionType": "git"
            },
            {
              "lessThan": "152983d87387f6a8ae72b73474cfa55fbcf1ec75",
              "status": "affected",
              "version": "77711d850bed75ae7142c3d1f22c1a8b4d049c33",
              "versionType": "git"
            },
            {
              "lessThan": "b5c037d6b807017e74a115288f81bc9cd5a5aab8",
              "status": "affected",
              "version": "6acfe25968913788d30ec0eedd80178c4ea3f1d0",
              "versionType": "git"
            },
            {
              "lessThan": "a6d5ce2e1a2d7bf189bde8a659d04b65f0b0725d",
              "status": "affected",
              "version": "d280c138e66be87d1fccfed42593f02fdb893905",
              "versionType": "git"
            },
            {
              "lessThan": "e24918ee67c4dc3d20d4670750e46e9b160365f4",
              "status": "affected",
              "version": "f32fea4c0234c971c12e46d76612cdc2dd4bb046",
              "versionType": "git"
            },
            {
              "lessThan": "37daa8c96bd563d03150e23f094cb60703594a6d",
              "status": "affected",
              "version": "46f781e0d151844589dc2125c8cce3300546f92a",
              "versionType": "git"
            },
            {
              "lessThan": "6493ebf9489efef0105078377b973ab33d51af22",
              "status": "affected",
              "version": "46f781e0d151844589dc2125c8cce3300546f92a",
              "versionType": "git"
            },
            {
              "lessThan": "8813b0612275cc61fe9e6603d0ee019247ade6be",
              "status": "affected",
              "version": "46f781e0d151844589dc2125c8cce3300546f92a",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "59bd04163e6451b9c7275277882ed9f4abfa2051",
              "versionType": "git"
            },
            {
              "lessThan": "5.10.261",
              "status": "affected",
              "version": "5.10.246",
              "versionType": "semver"
            },
            {
              "lessThan": "5.15.212",
              "status": "affected",
              "version": "5.15.196",
              "versionType": "semver"
            },
            {
              "lessThan": "6.1.178",
              "status": "affected",
              "version": "6.1.158",
              "versionType": "semver"
            },
            {
              "lessThan": "6.6.145",
              "status": "affected",
              "version": "6.6.114",
              "versionType": "semver"
            },
            {
              "lessThan": "6.12.97",
              "status": "affected",
              "version": "6.12.55",
              "versionType": "semver"
            },
            {
              "lessThan": "6.18",
              "status": "affected",
              "version": "6.17.5",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/hid/hid-multitouch.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.18"
            },
            {
              "lessThan": "6.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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-\u003emaxcontacts, which is taken from the device\u0027s\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 \u003c mt-\u003enum_slots; i++)\n\t\tclear_bit(i, \u0026td-\u003emt_io_flags);\n\nwith num_slots == maxcontacts. For maxcontacts around 250 the loop\nclears the bits that overlap td-\u003eapplications.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 \u0026 MT_IO_SLOTS_MASK\" arming checks become\nbitmap_empty(td-\u003eactive_slots, td-\u003emaxcontacts).\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."
    }
  ],
  "id": "CVE-2026-64364",
  "lastModified": "2026-07-27T05:16:43.347",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "ADJACENT_NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-25T10:17:19.110",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/12e90656e330ff8bbaf2f29c535fdb8a11cc6f55"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/152983d87387f6a8ae72b73474cfa55fbcf1ec75"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/37daa8c96bd563d03150e23f094cb60703594a6d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6493ebf9489efef0105078377b973ab33d51af22"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8813b0612275cc61fe9e6603d0ee019247ade6be"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a6d5ce2e1a2d7bf189bde8a659d04b65f0b0725d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b5c037d6b807017e74a115288f81bc9cd5a5aab8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e24918ee67c4dc3d20d4670750e46e9b160365f4"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.