CVE-2025-68780 — sched/deadline: only set free_cpus for online runqueues
In the Linux kernel, the following vulnerability has been resolved: sched/deadline: only set free_cpus for online runqueues Commit 16b269436b72 ("sched/deadline: Modify cpudl::free_cpus to reflect rd->online") introduced the cpudl_set/clear_freecpu functions to allow the cpu_dl::free_cpus mask to be manipulated by the deadline scheduler class rq_on/offline callbacks so the mask would also reflect this state. Commit 9659e1eeee28 ("sched/deadline: Remove cpu_active_mask from cpudl_find()") removed the check of the cpu_active_mask to save some processing on the premise that the cpudl::free_cpus mask already reflected the runqueue online state. Unfortunately, there are cases where it is possible for the cpudl_clear function to set the free_cpus bit for a CPU when the deadline runqueue is offline. When this occurs while a CPU is connected to the default root domain the flag may retain the bad state after the CPU has been unplugged. Later, a different CPU that is transitioning through the default root domain may push a deadline task to the powered down CPU when cpudl_find sees its free_cpus bit is set. If this happens the task will not have the opportunity to run. One example is outlined here: https://lore.kernel.org/lkml/20250110233010.2339521-1-opendmb@gmail.com Another occurs when the last deadline task is migrated from a CPU that has an offlined runqueue. The dequeue_task member of the deadline scheduler class will eventually call cpudl_clear and set the free_cpus bit for the CPU. This commit modifies the cpudl_clear function to be aware of the online state of the deadline runqueue so that the free_cpus mask can be updated appropriately. It is no longer necessary to manage the mask outside of the cpudl_set/clear functions so the cpudl_set/clear_freecpu functions are removed. In addition, since the free_cpus mask is now only updated under the cpudl lock the code was changed to use the non-atomic __cpumask functions.
Who exploits it and how urgent it is
A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.
How the score was calculated
- EPSS 0.2% (30-day exploitation probability)+2
The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).
Triage
Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.
Remediation
Fixes and mitigations documented by the sources — linked to the original advisory.
No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.
First 24 hours
Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.
- Identify exposed assets running the affected vendor/product/version combinations (Linux Linux).
- No fix documented in the sources: reduce exposure and monitor the vendor advisory.
- Search available logs for exploit probes, errors and authentication anomalies.
Affected scope
Vendor, product and versions as the sources word them.
| Vendor | Product | Versions | Status | Source |
|---|---|---|---|---|
| Linux | Linux | ≥ 9659e1eeee28f7025b6545934d644d19e9c6e603 and < 9019e399684e3cc68c4a3f050e268f74d69c1317≥ 9659e1eeee28f7025b6545934d644d19e9c6e603 and < fb36846cbcc936954f2ad2bffdff13d16c0be08a≥ 9659e1eeee28f7025b6545934d644d19e9c6e603 and < 91e448e69aca4bb0ba2e998eb3e555644db7322b≥ 9659e1eeee28f7025b6545934d644d19e9c6e603 and < dbc61834b0412435df21c71410562d933e4eba49≥ 9659e1eeee28f7025b6545934d644d19e9c6e603 and < 3ed049fbfb4d75b4e0b8ab54c934f485129d5dc8≥ 9659e1eeee28f7025b6545934d644d19e9c6e603 and < 382748c05e58a9f1935f5a653c352422375566eaversion 4.0 | Vulnerable | CVE Program (cve.org) e CISA ADP |
EPSS over time FIRST
Oct 13, 2026 → Oct 15, 2026 · 3 reading(s) · max 0.21%
Detection
Read off the CVSS vector and the weakness class. Starting points, not tested rules.
- Not enough vector or weakness data: use the affected application’s logs as a starting point.
Timeline
What happened to this CVE, newest first.
- 2026
- Record published
- Affected products added · linux/linux
- Source status changed · → Deferred
- Record created in this database
- CVE published
Source activity
Repeated readings are counted rather than listed.
- 1× Official description updated · Oct 13, 2026 – Oct 13, 2026
References
6 on the record
- git.kernel.org/stable/c/fb36846cbcc936954f2ad2bffdff13d16c0be08a
- git.kernel.org/stable/c/382748c05e58a9f1935f5a653c352422375566ea
- git.kernel.org/stable/c/9019e399684e3cc68c4a3f050e268f74d69c1317
- git.kernel.org/stable/c/dbc61834b0412435df21c71410562d933e4eba49
- git.kernel.org/stable/c/91e448e69aca4bb0ba2e998eb3e555644db7322b
- git.kernel.org/stable/c/3ed049fbfb4d75b4e0b8ab54c934f485129d5dc8
Elsewhere on this site
Related CVEs (same products)
- Critical CVE-2026-99999 ipv4: validate checksum_start before completing checksum 1d
- Unknown CVE-2026-98432 ipv4: free inet_opt and ireq_opt after an RCU grace period 1d
- Unknown CVE-2026-98424 wifi: cfg80211: undo netns switch if renaming the wiphy fails 2d
- Unknown CVE-2026-98425 wifi: mac80211: don't warn when an IBSS has no channel to scan 2d
- Unknown CVE-2026-98426 wifi: mwifiex: fix IRQ leak using wrong index in MSI-X error path 2d
- Unknown CVE-2026-98427 net/sched: codel: bound the dropping loop per dequeue call 2d
Not in any source we poll
Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.
- No CVSS score published by NVD, the CNA, CISA or GitHub so far.
- No fixed version, patch or mitigation documented.
- No CISA SSVC assessment.
- No CWE classification.
- No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
- No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
- No exploit packet captures, log samples, or incident case IDs supplied.
Answered from this record
Text assembled only from the fields above — no additional claims.
What should defenders know first?
CVE-2025-68780 is "sched/deadline: only set free_cpus for online runqueues", rated Unknown. It affects Linux (Linux); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. EPSS 0.21% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.
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