In the Linux kernel, the following vulnerability has been resolved: s390/cio: Fix device...

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.

Basic information

Type
unreviewed
Severity
medium
Advisory on GitHub
Open advisory ↗
Repository advisory
Source code
Not specified
Published (advisory)
2026-05-27 15:33:19 UTC
Updated
2026-06-16 03:31:35 UTC
NVD published
2026-05-27

EPSS Score

Score Percentile
0.02% 7.38%

CVSS Scores

Base score Version Severity Vector
5.5 3.1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.

Identifiers

CWEs

CWE id Name
CWE-401 Missing Release of Memory after Effective Lifetime

References

cvelogic Threat Intelligence