CVE-2026-98859: HID: multitouch: stop the release timer from being rearmed on remove
HID: multitouch: stop the release timer from being rearmed on remove
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
azurelinux/kernelto a version that resolves this vulnerability.Fixed in 6.6.161.1-1 - Configuration
Replace timer_delete_sync(&td->release_timer) with timer_shutdown_sync(&td->release_timer) before hid_hw_stop(hdev), so later mod_timer() calls cannot rearm the timer.
Linux kernel HID multitouch release timer teardown in mt_remove() = timer_shutdown_sync()
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Systems using the Linux kernel HID multitouch driver are exposed when the sticky-finger quirk is active. The vulnerable condition involves removal or unbinding of the HID device while the transport can still deliver reports.
What must happen for exploitation or failure to occur?
A report must arrive after the release timer has been deleted during device removal, causing the report path to arm the timer again. Once the driver is unbound and its device data is freed, the subsequently firing timer can dereference freed memory.
How can I determine whether a kernel contains the resolution?
Check the kernel source or applied stable patches for the referenced commits: 1f1bd9a3117f082eb891c0986c4f0e04cd974c9a, 0c19a6c1d25fd5ed66d1f80dc6f6e56cc1f0a787, or a0125ca86e405b8a704e96157a6c10ca51087652. The resolved behavior must prevent the release timer from being rearmed after teardown begins.