CVE-2026-45981

Summary

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.

Impact & exploitability

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/6715560527e343a387e4a0d2e6c401748e89fa55 ↗

Additional information

• NVD record
• https://git.kernel.org/stable/c/6715560527e343a387e4a0d2e6c401748e89fa55Patch
• https://git.kernel.org/stable/c/abb6e07f46a740cda4f07d1b561ae4eaa7a1df42Patch
• https://git.kernel.org/stable/c/c35cfbb5341ba05ad1b4476ffc3c21cc3ff8f603Patch
• https://git.kernel.org/stable/c/f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7Patch
• https://git.kernel.org/stable/c/f96c5ccf95ae5f27218c1ce2d6a3ad2d3e105424Patch