CVE-2025-38594

High

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Fix UAF on sva unbind with pending IOPFs Commit 17fce9d2336d ("iommu/vt-d: Put iopf enablement in domain attach path") disables IOPF on device by removing the device from its IOMMU's IOPF queue when the last IOPF-capable domain is detached from the device. Unfortunately, it did this in a wrong place where there are still pending IOPFs. As a result, a use-after-free error is potentially triggered and eventually a kernel panic with a kernel trace similar to the following: refcount_t: underflow; use-after-free. WARNING: CPU: 3 PID: 313 at lib/refcount.c:28 refcount_warn_saturate+0xd8/0xe0 Workqueue: iopf_queue/dmar0-iopfq iommu_sva_handle_iopf Call Trace: <TASK> iopf_free_group+0xe/0x20 process_one_work+0x197/0x3d0 worker_thread+0x23a/0x350 ? rescuer_thread+0x4a0/0x4a0 kthread+0xf8/0x230 ? finish_task_switch.isra.0+0x81/0x260 ? kthreads_online_cpu+0x110/0x110 ? kthreads_online_cpu+0x110/0x110 ret_from_fork+0x13b/0x170 ? kthreads_online_cpu+0x110/0x110 ret_from_fork_asm+0x11/0x20 </TASK> ---[ end trace 0000000000000000 ]--- The intel_pasid_tear_down_entry() function is responsible for blocking hardware from generating new page faults and flushing all in-flight ones. Therefore, moving iopf_for_domain_remove() after this function should resolve this.

Package Linux Kernel
Published 2025-08-19
Last modified 2025-11-26
CVSS version 3.1
Patch available
Yes

CVSS 3.1 score

7.8

out of 10
High
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Weakness type

CWE-416

CVE-2025-38594 is a Use After Free vulnerability

What is Use After Free?

The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. Learn more on MITRE CWE

Affected versions

Linux kernel versions 6.16 and later are affected. Fixed in 6.16.1, 6.17 and their respective stable series.

Affected from
≥ 6.16
Fixed in
✓ 6.16.1 6.16.x ✓ 6.17

References

The following references provide additional information about CVE-2025-38594 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2025-38594?

    CVE-2025-38594 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 , classified as an Use After Free flaw (CWE-416) . It affects Linux kernel versions from 6.16 onward and has been patched in 6.16.1 and 6.17. CVE-2025-38594 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • What is the CVSS score for CVE-2025-38594?

    CVE-2025-38594 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H .

  • Is there a patch available for CVE-2025-38594?

    Yes — CVE-2025-38594 has been patched. Fixed versions include 6.16.1 and 6.17. If you are running Linux kernel 6.16 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2025-38594 actively exploited?

    No — CVE-2025-38594 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

  • What is Use After Free (CWE-416)?

    The product references memory after it has been freed, which may cause it to crash, use unexpected values, or execute code. View CWE-416 on MITRE CWE →