CVE-2026-64438: crypto: qat - fix VF2PF work teardown race in adf_disable_sriov()

From: Greg Kroah-Hartman <[email protected]>

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.

The Linux kernel CVE team has assigned CVE-2026-64438 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 4.3 with commit ed8ccaef52fa03fb03cff45b380f72c9f869f273 and fixed in 5.10.261 with commit 218c2836b3987f3fa1d9eac505462cded0821e4c
	Issue introduced in 4.3 with commit ed8ccaef52fa03fb03cff45b380f72c9f869f273 and fixed in 5.15.212 with commit 446b4d77599cf1a168573f7fb32a4a6aa4f09219
	Issue introduced in 4.3 with commit ed8ccaef52fa03fb03cff45b380f72c9f869f273 and fixed in 6.1.178 with commit 5d916c1eae1933511a69bffe243b4ee5d7da399c
	Issue introduced in 4.3 with commit ed8ccaef52fa03fb03cff45b380f72c9f869f273 and fixed in 6.6.145 with commit f344a369d0380d54c8d6c8d24734a78dd5a89817
	Issue introduced in 4.3 with commit ed8ccaef52fa03fb03cff45b380f72c9f869f273 and fixed in 6.12.97 with commit 51144032248cc4ea22917370565650670b8b4e9b
	Issue introduced in 4.3 with commit ed8ccaef52fa03fb03cff45b380f72c9f869f273 and fixed in 6.18.40 with commit 49cd5ac6de8de39a14ead609bb552d372d5602cd
	Issue introduced in 4.3 with commit ed8ccaef52fa03fb03cff45b380f72c9f869f273 and fixed in 7.1.4 with commit 6e92b28cd74fa433658efeadf21b9d4b01023d7d
	Issue introduced in 4.3 with commit ed8ccaef52fa03fb03cff45b380f72c9f869f273 and fixed in 7.2-rc1 with commit 277281c10c63791067d24d421f7c43a15faa9096

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-64438
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/crypto/intel/qat/qat_common/adf_accel_devices.h
	drivers/crypto/intel/qat/qat_common/adf_common_drv.h
	drivers/crypto/intel/qat/qat_common/adf_isr.c
	drivers/crypto/intel/qat/qat_common/adf_sriov.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	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