CVE Catalog

CVE-2026-80766

Unknown
Published: Translated: NVD NIST

Summary

A use-after-free vulnerability was found in the Linux kernel's uclogic HID driver. The issue involves the inrange_timer which can be re-armed after cancellation during device removal, leading to a dereference of freed memory when the timer expires.

Risk Assessment

The vulnerability may lead to kernel memory corruption, potentially causing a system crash or privilege escalation in kernel context. However, exploitation requires physical access to the device or a specially crafted HID report.

Recommendation

Apply the official Linux kernel patch immediately, which changes the teardown order to use timer_shutdown_sync() before hid_hw_stop(). Also update the system to a kernel version containing the fix.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: HID: uclogic: fix use-after-free of inrange_timer on remove uclogic_remove() cancels the pen in-range timer and then stops the device: timer_delete_sync(&drvdata->inrange_timer); hid_hw_stop(hdev); timer_delete_sync() only guarantees the timer is idle at that instant. uclogic_raw_event_pen() keeps delivering pen reports until hid_hw_stop() stops the transport several lines later, and every report with pen->inrange == UCLOGIC_PARAMS_PEN_INRANGE_NONE re-arms the timer: mod_timer(&drvdata->inrange_timer, jiffies + msecs_to_jiffies(100)); A report landing between the timer_delete_sync() call and the transport teardown in hid_hw_stop() re-arms inrange_timer after it was cancelled. uclogic_remove() then returns and the devm drvdata is freed, while hid_hw_stop() has already freed the input device drvdata->pen_input points at, so when the timer fires ~100 ms later uclogic_inrange_timeout() dereferences freed memory -- a use-after-free in timer-softirq context. Swapping the two calls is not a fix: stopping the device first frees drvdata->pen_input via hidinput_disconnect() while the timer may still be pending, so a timer already armed before removal fires on the freed input device in the window before timer_delete_sync() runs. Use timer_shutdown_sync() before hid_hw_stop() instead. It cancels the timer, waits for a running callback while pen_input is still valid, and prevents any further re-arming -- a later mod_timer() from an in-flight report is silently ignored -- so the timer is provably dead before hid_hw_stop() frees the inputs. This is the ordering the timer core documents for this "timer re-armed from another path" teardown case.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS