Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: iommu/s390: Fix memory corruption when using identity domain zpci_get_iommu_ctrs() returns counter information to be reported as part of device statistics; these counters are stored as part of the s390_domain. The problem, however, is that the identity domain is not backed by an s390_domain and so the conversion via to_s390_domain() yields a bad address that is zero'd initially and read on-demand later via a sysfs read. These counters aren't necessary for the identity domain; just return NULL in this case. This issue was discovered via KASAN with reports that look like: BUG: KASAN: global-out-of-bounds in zpci_fmb_enable_device when using the identity domain for a device on s390.
CVSS Score
HIGH
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | >= 6.15, < 6.16.9 |
Related Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/17a58caf3863163c4a84a218a9649be2c8061443Patch
- https://git.kernel.org/stable/c/b3506e9bcc777ed6af2ab631c86a9990ed97b474Patch
FAQ
What is CVE-2025-39939?
CVE-2025-39939 is a vulnerability with a CVSS score of 7.8 (HIGH). In the Linux kernel, the following vulnerability has been resolved: iommu/s390: Fix memory corruption when using identity domain zpci_get_iommu_ctrs() returns counter information to be reported as p...
How severe is CVE-2025-39939?
CVE-2025-39939 has been rated HIGH with a CVSS base score of 7.8/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-39939?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel.