CVE-2026-52976

When xe_hw_engine_group_add_exec_queue() fails, the error path jumps to put_exec_queue which skips xe_exec_queue_kill(). If the VM is in preempt fence mode, xe_vm_add_compute_exec_queue() has already added the queue to the VM's compute exec queue list. Skipping the kill leaves the queue on that list, leading to a dangling pointer after the queue is freed.
When xa_alloc() fails after xe_hw_engine_group_add_exec_queue() has succeeded, the error path does not call xe_hw_engine_group_del_exec_queue() to remove the queue from the hw engine group list. The queue is then freed while still linked into the hw engine group, causing a use-after-free.

Fix both by:

Changing the xe_hw_engine_group_add_exec_queue() failure path to jump to kill_exec_queue so that xe_exec_queue_kill() properly removes the queue from the VM's compute list.
Adding a del_hw_engine_group label before kill_exec_queue for the xa_alloc() failure path, which removes the queue from the hw engine group before proceeding with the rest of the cleanup.

(cherry picked from commit 37c831f401746a45d510b312b0ed7a77b1e06ec8)

Database specific

{
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/52xxx/CVE-2026-52976.json"
}

References

Affected packages

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

7970cb36966c9b9183255dc097ae0446300eebcf

Fixed

f93b00161213a0fe9f7ff1d8498ee5ca9e0a5c43

Fixed

753b149d5a433eb19e0c1b0eb4526a6e26120d1f

Fixed

1be55646d8a2035343b012dcb12210db7bb8b056

Fixed

f3cc22d4df3ed58439ea7e21daa54c3608e03b78

source

"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-52976.json"

source

"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-52976.json"