Bug 2429077 (CVE-2025-71073)

Summary: CVE-2025-71073 kernel: Input: lkkbd - disable pending work before freeing device
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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OS: Linux   
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Description OSIDB Bzimport 2026-01-13 16:05:06 UTC 
In the Linux kernel, the following vulnerability has been resolved:

Input: lkkbd - disable pending work before freeing device

lkkbd_interrupt() schedules lk->tq via schedule_work(), and the work
handler lkkbd_reinit() dereferences the lkkbd structure and its
serio/input_dev fields.

lkkbd_disconnect() and error paths in lkkbd_connect() free the lkkbd
structure without preventing the reinit work from being queued again
until serio_close() returns. This can allow the work handler to run
after the structure has been freed, leading to a potential use-after-free.

Use disable_work_sync() instead of cancel_work_sync() to ensure the
reinit work cannot be re-queued, and call it both in lkkbd_disconnect()
and in lkkbd_connect() error paths after serio_open().
Comment 1 Jon Moroney 2026-01-15 01:01:28 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026011325-CVE-2025-71073-b002@gregkh/T