CVE-2026-45981: Linux Kernel

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: s390/cio: Fix device lifecycle handling in css_alloc_subchannel() `css_alloc_subchannel()` calls `device_initialize()` before setting up the DMA masks. If `dma_set_coherent_mask()` or `dma_set_mask()` fails, the error path frees the subchannel structure directly, bypassing the device model reference counting. Once `device_initialize()` has been called, the embedded struct device must be released via `put_device()`, allowing the release callback to free the container structure. Fix the error path by dropping the initial device reference with `put_device()` instead of calling `kfree()` directly. This ensures correct device lifetime handling and avoids potential use-after-free or double-free issues.

Affected products

• Linux Linux Kernel: from 3.10, before 6.6.128 (fixed in 6.6.128); from 6.7, before 6.12.75 (fixed in 6.12.75); from 6.13, before 6.18.14 (fixed in 6.18.14); from 6.19, before 6.19.4 (fixed in 6.19.4)

Published 2026-05-27. Last modified 2026-06-17.