CVE-2026-64438

What is known

In the Linux kernel, the following vulnerability has been resolved: crypto: qat - fix VF2PF work teardown race in adf_disable_sriov() The VF2PF interrupt handler queues PF-side response work that stores a raw pointer to per-VF state (struct adf_accel_vf_info). Currently, adf_disable_sriov() destroys per-VF mutexes and frees vf_info without stopping new VF2PF work or waiting for in-flight workers to complete. A concurrently scheduled or already queued worker can then dereference freed memory. This manifests as a use-after-free when KASAN is enabled: BUG: KASAN: null-ptr-deref in mutex_lock+0x76/0xe0 Write of size 8 at addr 0000000000000260 by task kworker/24:2/... Workqueue: qat_pf2vf_resp_wq adf_iov_send_resp [intel_qat] Call Trace: kasan_report+0x119/0x140 mutex_lock+0x76/0xe0 adf_gen4_pfvf_send+0xd4/0x1f0 [intel_qat] adf_recv_and_handle_vf2pf_msg+0x290/0x360 [intel_qat] adf_iov_send_resp+0x8c/0xe0 [intel_qat] process_one_work+0x6ac/0xfd0 worker_thread+0x4dd/0xd30 kthread+0x326/0x410 ret_from_fork+0x33b/0x670 Add a PF-local flag, vf2pf_disabled, that gates work queueing, worker processing, and interrupt re-enabling during teardown. Set this flag atomically with the hardware interrupt mask inside adf_disable_all_vf2pf_interrupts(). After masking, synchronize the AE cluster MSI-X interrupt and flush the PF response workqueue before tearing down per-VF locks and state so all in-flight work completes before vf_info is destroyed. Introduce adf_enable_all_vf2pf_interrupts() to clear the flag and unmask all VF2PF interrupts under the same lock when SR-IOV is re-enabled. This ensures the software flag and hardware state transition atomically on both the enable and disable paths.

Business impact

Successful exploitation of CVE-2026-64438, a high vulnerability (CVSS 8.8) affecting the affected product, may affect the confidentiality, integrity or availability of the vulnerable environment. The exact impact depends on the installed version, exposed interfaces and deployment configuration.

Recommended administrator action

Confirm whether the affected product is present and compare installed versions with the vendor advisory and NVD record. Apply the vendor patch or documented mitigation; until remediation is complete, reduce exposure of affected interfaces, review relevant logs and monitor for indicators of exploitation. DataHouse can support version verification, managed patching, network exposure reduction, log review and backup validation for dedicated, cloud and colocated environments.

Sources

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