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Fencer Vulns
no cvss —

CVE-2026-98859 json

HID: multitouch: stop the release timer from being rearmed on remove

published 2026-10-18 21 d ago modified 2026-10-21 18 d ago also EUVD-2026-103799

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

HID: multitouch: stop the release timer from being rearmed on remove

mt_remove() quiesces the sticky-finger timer before stopping the hardware:

timer_delete_sync(&td->release_timer);

sysfs_remove_group(&hdev->dev.kobj, &mt_attribute_group); hid_hw_stop(hdev);

timer_delete_sync() waits for a running callback and dequeues the timer, but it does not stop the timer from being armed again. The transport is still delivering reports at that point, and the report path rearms it:

if (app->quirks & MT_QUIRK_STICKY_FINGERS) { if (td->mt_io_flags & MT_IO_SLOTS_MASK) mod_timer(&td->release_timer, jiffies + msecs_to_jiffies(100));

A report that arrives after timer_delete_sync() has returned therefore leaves the timer queued. td is allocated with devm_kzalloc() against hdev->dev, so it is freed when the driver is unbound, after mt_remove() returns. When the timer fires afterwards, mt_expired_timeout() dereferences the freed td:

struct mt_device *td = timer_container_of(td, t, release_timer); struct hid_device *hdev = td->hdev;

if (test_and_set_bit_lock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags))

Simply moving the teardown after hid_hw_stop() does not fix this on its own, because mt_expired_timeout() calls mt_release_contacts(), which walks hdev->inputs; the timer still has to be quiesced before hid_hw_stop() tears the input devices down.

Use timer_shutdown_sync() instead, which additionally makes any later mod_timer() a no-op, so neither ordering constraint has to be traded off against the other. This is the final-teardown pattern the function was introduced for, and hid-wiimote already uses it for the same reason.

Patch / fix

  • Linux Linux 6.6.160, 6.12.113, 6.18.56, 7.2.10, 7.3
  • linux Debian 13 6.12.113-1
  • linux Debian 14 7.2.10-1
  • linux-6.12 Debian 12 6.12.113-1~deb12u1

debian advisories DEBIAN-CVE-2026-98859

  • kernel Azure Linux 3.0 6.6.161.1-1

azure linux advisories AZL-108818

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-98859 updated cvss 5.3

kernel: kernel: Denial of service via use-after-free in HID multitouch driver

  • Red Hat Enterprise Linux 10 kernel
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.16% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

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