HID: multitouch: fix out-of-bounds bit access on mt_io_flags
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
CVE-2026-64364
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-64364
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
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"versionType": "git"
},
{
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"versionType": "git"
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{
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{
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{
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{
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{
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{
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"versionType": "git"
},
{
"status": "affected",
"version": "59bd04163e6451b9c7275277882ed9f4abfa2051",
"versionType": "git"
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{
"status": "affected",
"version": "5.10.246",
"lessThan": "5.10.261",
"versionType": "semver"
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{
"status": "affected",
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"versionType": "semver"
},
{
"status": "affected",
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"lessThan": "6.1.178",
"versionType": "semver"
},
{
"status": "affected",
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"lessThan": "6.6.145",
"versionType": "semver"
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{
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"version": "6.12.55",
"lessThan": "6.12.97",
"versionType": "semver"
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{
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"version": "6.17.5",
"lessThan": "6.18",
"versionType": "semver"
}
],
"programFiles": [
"drivers/hid/hid-multitouch.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
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{
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"version": "0",
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{
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"version": "5.10.261",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
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{
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"version": "5.15.212",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
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},
{
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"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
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"version": "6.12.97",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/hid/hid-multitouch.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-64364
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #41014 · Revision 1
- Added to Heist Feed
- Publisher date