CVE-2026-80642: liveupdate: Reference count incoming FLB data
In the Linux kernel, the following vulnerability has been resolved:
liveupdate: Reference count incoming FLB data
Increment the incoming FLB refcount in liveupdateflbgetincoming() so that the FLB structure cannot be freed while the caller is actively using it. Add an additional liveupdateflbputincoming() function so the caller can explicitly indicate when it is done using the FLB data.
During a Live Update, a subsystem might need to hold onto the incoming File-Lifecycle-Bound (FLB) data for an extended period, such as during device enumeration. Incrementing the reference count guarantees that the data remains valid and accessible until the subsystem releases it, preventing future use-after-free bugs.
Event History
Frequently Asked Questions
When could this issue be triggered?
It can arise during a Live Update when a subsystem retains incoming File-Lifecycle-Bound (FLB) data for an extended period, such as while performing device enumeration.
What condition leads to the use-after-free risk?
The incoming FLB structure could be freed while a caller was still using it because obtaining the incoming data did not increment its reference count.
What does the fix change?
The fix increments the incoming FLB reference count when the data is obtained and adds liveupdate_flb_put_incoming() so callers explicitly release the reference after they finish using the FLB data.