CVE-2026-45981

Description

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.

References

• https://git.kernel.org/stable/c/2b2ad7ad4a28ffdb9f94e6d979b88a5b12b71681
• https://git.kernel.org/stable/c/6715560527e343a387e4a0d2e6c401748e89fa55
• https://git.kernel.org/stable/c/abb6e07f46a740cda4f07d1b561ae4eaa7a1df42
• https://git.kernel.org/stable/c/b1d4e6fb241672850296956c4d782a69363a3807
• https://git.kernel.org/stable/c/c35cfbb5341ba05ad1b4476ffc3c21cc3ff8f603