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CVE-2025-38594

HIGHCVSS 7.8/10EPSS 0.14%

Last modified

CVE-2025-38594 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. 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. EPSS estimates a 0.14% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.14%

3.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
LinuxLinux Kernel6.16

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2025-38594?
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.
How severe is CVE-2025-38594?
CVE-2025-38594 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.14% probability of exploitation in the next 30 days.
How do I fix CVE-2025-38594?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST