CVE-2025-39939
BaseFortify
Publication date: 2025-10-04
Last updated on: 2026-03-25
Assigner: kernel.org
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | From 5.15.160 (inc) to 5.16 (inc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability in the Linux kernel involves memory corruption when using the identity domain in the iommu/s390 subsystem. Specifically, a function called zpci_get_iommu_ctrs() returns device counter information stored in an s390_domain structure. However, the identity domain is not backed by an s390_domain, so converting it via to_s390_domain() results in an invalid address. This leads to reading from a zeroed address on-demand, causing memory corruption detected by KASAN.
How can this vulnerability impact me? :
The vulnerability can cause memory corruption in the Linux kernel when using the identity domain on s390 devices. This could lead to system instability, crashes, or unexpected behavior when device statistics are accessed, potentially affecting the reliability and security of systems using this configuration.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by monitoring kernel logs for KASAN (Kernel Address Sanitizer) reports indicating global-out-of-bounds errors related to zpci_fmb_enable_device when using the identity domain on s390 architecture. You can check for such errors using the command: dmesg | grep -i kasan
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, update your Linux kernel to a version where the fix for the identity domain memory corruption in iommu/s390 has been applied. Avoid using the identity domain for devices on s390 until the patch is applied.