Bug 2436780 (CVE-2026-23063)

Summary: CVE-2026-23063 kernel: uacce: ensure safe queue release with state management
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 2026-02-04 17:03:02 UTC 
In the Linux kernel, the following vulnerability has been resolved:

uacce: ensure safe queue release with state management

Directly calling `put_queue` carries risks since it cannot
guarantee that resources of `uacce_queue` have been fully released
beforehand. So adding a `stop_queue` operation for the
UACCE_CMD_PUT_Q command and leaving the `put_queue` operation to
the final resource release ensures safety.

Queue states are defined as follows:
- UACCE_Q_ZOMBIE: Initial state
- UACCE_Q_INIT: After opening `uacce`
- UACCE_Q_STARTED: After `start` is issued via `ioctl`

When executing `poweroff -f` in virt while accelerator are still
working, `uacce_fops_release` and `uacce_remove` may execute
concurrently. This can cause `uacce_put_queue` within
`uacce_fops_release` to access a NULL `ops` pointer. Therefore, add
state checks to prevent accessing freed pointers.
Comment 1 Jon Moroney 2026-02-04 23:59:32 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026020415-CVE-2026-23063-d727@gregkh/T