VulnerabilityPublished 27 May 2026Updated 6 Nov 2026

CVE-2026-45981: Linux kernel · s390/cio: Fix device lifecycle handling in css_alloc_subchannel()

Affects Linux kernelSource CVE Database V5

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Not known to be exploited · fixed in f96c5ccf95ae5f27218c1ce2d6a3ad2d3e105424 : update Linux kernel when convenient.

Data as of 6 Nov 2026, 16:34 UTC

Severity

Unrated

Rated by Threat Radar · No CVSS score from NVD or the CNA

Thin evidence

One scorer or none

Exploitation: No evidence of active exploitation and no public proof of concept
Automatable: Attackers cannot reliably automate steps 1–4 of the kill chain
Technical impact: Limited control over the software or limited information exposure

CISA SSVC assessment, 2026-11-06.

Patch

Available – fixed in f96c5ccf95ae5f27218c1ce2d6a3ad2d3e105424, f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7, c35cfbb5341ba05ad1b4476ffc3c21cc3ff8f603 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ e5dcf0025d7af58f525590ac86ac27cb44714e8d, < f96c5ccf95ae5f27218c1ce2d6a3ad2d3e105424	Fixed in f96c5ccf95ae5f27218c1ce2d6a3ad2d3e105424
LinuxLinux	Affected ≥ e5dcf0025d7af58f525590ac86ac27cb44714e8d, < f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7	Fixed in f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7
LinuxLinux	Affected ≥ e5dcf0025d7af58f525590ac86ac27cb44714e8d, < c35cfbb5341ba05ad1b4476ffc3c21cc3ff8f603	Fixed in c35cfbb5341ba05ad1b4476ffc3c21cc3ff8f603
LinuxLinux	Affected ≥ e5dcf0025d7af58f525590ac86ac27cb44714e8d, < abb6e07f46a740cda4f07d1b561ae4eaa7a1df42	Fixed in abb6e07f46a740cda4f07d1b561ae4eaa7a1df42
LinuxLinux	Affected ≥ e5dcf0025d7af58f525590ac86ac27cb44714e8d, < 6715560527e343a387e4a0d2e6c401748e89fa55	Fixed in 6715560527e343a387e4a0d2e6c401748e89fa55
LinuxLinux	Affected =3.10	Fixed in–

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

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