CVE-2026-45981
Published: May 28, 2026Last modified: June 24, 2026
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.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 5.5 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Vulnerable (6.1.174-r0) |
| 25 LTS | linux-lts | Fixed (6.12.80-r0) | |
| Stream | linux-lts | Fixed (6.18.35-r1) |
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
- https://git.kernel.org/stable/c/f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7
- https://git.kernel.org/stable/c/f96c5ccf95ae5f27218c1ce2d6a3ad2d3e105424
- https://git.kernel.org/stable/c/fd295a75d828c11acfcc6869c2a12cdaaf9b7722