CVE-2025-39939

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux64af12c6ec3afd7d44bc8b2044eee59f98059087 < 17a58caf3863163c4a84a218a9649be2c8061443affected
LinuxLinux64af12c6ec3afd7d44bc8b2044eee59f98059087 < b3506e9bcc777ed6af2ab631c86a9990ed97b474affected
LinuxLinux6.15affected
LinuxLinux0 < 6.15unaffected
LinuxLinux6.16.9 <= 6.16.*unaffected
LinuxLinux6.17 <= *unaffected

Weaknesses

References