Bug 2524468 (CVE-2026-80572)

Summary: CVE-2026-80572 kernel: Input: byd - synchronize timer deletion before freeing private data
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's byd input driver. A race condition exists during device disconnection where the `byd_disconnect()` function frees private data before ensuring that a timer callback, `byd_clear_touch()`, has completed. This can lead to the callback attempting to access memory after it has been freed, potentially resulting in system instability or denial of service.
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Description OSIDB Bzimport 2026-08-26 14:57:58 UTC 
In the Linux kernel, the following vulnerability has been resolved:

Input: byd - synchronize timer deletion before freeing private data

byd_disconnect() uses timer_delete() before freeing the driver's private
data.  This does not wait for a running byd_clear_touch() callback, which
dereferences the private data and its psmouse pointer.  A callback racing
with disconnect can therefore access the private data after it has been
freed.  The timer can also still be re-armed by byd_process_byte() while
the disconnect is in progress.

Use timer_shutdown_sync() before freeing the private data: it waits for
a running callback and turns any later re-arm attempt into a no-op.
Comment 1 gkamathe 2026-08-27 10:24:48 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082613-CVE-2026-80572-fc32@gregkh/T