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VulnerabilityPublished Updated

CVE-2026-64438: Linux kernel · Use After Free

Affects Linux kernelSource CVE Database V5

0

Not known to be exploited · CVSS 8.8 High · fixed in f344a369d0380d54c8d6c8d24734a78dd5a89817 : patch Linux kernel soon.

Data as of 26 Oct 2026, 17:16 UTC

CVSS 3.1 base score
8.8High
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.1% chance of exploitation in 30 days – higher than 2% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CISA SSVC
Exploitation
No evidence of active exploitation and no public proof of concept
Automatable
Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact
Total control over the software or total information disclosure

CISA SSVC assessment, 2026-10-16.

Patch
Available – fixed in f344a369d0380d54c8d6c8d24734a78dd5a89817, 51144032248cc4ea22917370565650670b8b4e9b, 277281c10c63791067d24d421f7c43a15faa9096 +5
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 25 Jul 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
LinuxLinuxAffected
  • ≥ ed8ccaef52fa03fb03cff45b380f72c9f869f273, < f344a369d0380d54c8d6c8d24734a78dd5a89817
Fixed in
  • f344a369d0380d54c8d6c8d24734a78dd5a89817
LinuxLinuxAffected
  • ≥ ed8ccaef52fa03fb03cff45b380f72c9f869f273, < 51144032248cc4ea22917370565650670b8b4e9b
Fixed in
  • 51144032248cc4ea22917370565650670b8b4e9b
LinuxLinuxAffected
  • ≥ ed8ccaef52fa03fb03cff45b380f72c9f869f273, < 277281c10c63791067d24d421f7c43a15faa9096
Fixed in
  • 277281c10c63791067d24d421f7c43a15faa9096
LinuxLinuxAffected
  • ≥ ed8ccaef52fa03fb03cff45b380f72c9f869f273, < 446b4d77599cf1a168573f7fb32a4a6aa4f09219
Fixed in
  • 446b4d77599cf1a168573f7fb32a4a6aa4f09219
LinuxLinuxAffected
  • ≥ ed8ccaef52fa03fb03cff45b380f72c9f869f273, < 218c2836b3987f3fa1d9eac505462cded0821e4c
Fixed in
  • 218c2836b3987f3fa1d9eac505462cded0821e4c
LinuxLinuxAffected
  • ≥ ed8ccaef52fa03fb03cff45b380f72c9f869f273, < 49cd5ac6de8de39a14ead609bb552d372d5602cd
Fixed in
  • 49cd5ac6de8de39a14ead609bb552d372d5602cd

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.

References

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