CVE-2025-38594

iommu/vt-d: Fix UAF on sva unbind with pending IOPFs

HIGH
7.8
CVSS Score
Published: August 19, 2025 at 05:03 PM UTC
Updated: August 5, 2026 at 12:44 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.2%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.16 ≤ v < 6.16.16.16 ≤ v < 6.1717fce9d2336d952b95474248303e5e7d9777f2e06.16
Vendor states this is fixed in c68332b7ee893292bba6e87d31ef2080c066c65d (fixed)
Vendor states this is fixed in f0b9d31c6edd50a6207489cd1bd4ddac814b9cd2 (fixed)
Vendor states this is fixed in 6.16 (unaffected)
Vendor states this is fixed in 6.16.1 (unaffected)
Vendor states this is fixed in 6.17 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c68332b7ee893292bba6e87d31ef2080c066c65d
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/f0b9d31c6edd50a6207489cd1bd4ddac814b9cd2

CVSS

7.8HIGHLinux
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-416

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