CVE-2026-64438

Summary

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.

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/218c2836b3987f3fa1d9eac505462cded0821e4c
• https://git.kernel.org/stable/c/446b4d77599cf1a168573f7fb32a4a6aa4f09219
• https://git.kernel.org/stable/c/5d916c1eae1933511a69bffe243b4ee5d7da399c
• https://git.kernel.org/stable/c/f344a369d0380d54c8d6c8d24734a78dd5a89817
• https://git.kernel.org/stable/c/51144032248cc4ea22917370565650670b8b4e9b
• https://git.kernel.org/stable/c/49cd5ac6de8de39a14ead609bb552d372d5602cd
• https://git.kernel.org/stable/c/6e92b28cd74fa433658efeadf21b9d4b01023d7d
• https://git.kernel.org/stable/c/277281c10c63791067d24d421f7c43a15faa9096

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