0.0
NA
CVE-2026-99104
sched_ext: Fix the bypass dispatch claim for schedulers bypassed by an ancestor
Description

In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix the bypass dispatch claim for schedulers bypassed by an ancestor scx_bypass() claims bypass dispatch when the scheduler's depth goes from zero to one and releases it when the depth returns to zero, but propagates only the depth to the descendants, not the claim. A descendant that starts bypassing with its ancestor never claims, and one whose own bypass ends under the ancestor's keeps its claim, as its depth does not return to zero. A sub-scheduler enable whose bypass ends under a PM suspend thus leaks its claim: the parent keeps hosting bypass dispatch and the sub-scheduler's next bypass trips the WARN_ON_ONCE() on the claim. A sub-scheduler disable that starts under a PM suspend has no claim, so once the resume lifts the root's bypass its tasks sit on the parent's bypass DSQs with nobody consuming them. Claim for every descendant whose depth goes from zero to one in the propagation and release every scheduler in the subtree whose depth returned to zero once the tasks have moved out of the bypass DSQs. A parent that is bypassing itself when a descendant claims consumes only its own bypass DSQs, empty until it leaves bypass and becomes the host.

INFO

Published Date :

Oct. 28, 2026, 11:17 a.m.

Last Modified :

Oct. 28, 2026, 11:17 a.m.

Remotely Exploit :

No

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products

The following products are affected by CVE-2026-99104 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
Solution
Apply kernel patches to correctly manage bypass dispatch claims in sched_ext.
  • Update the Linux kernel to the latest fixed version.
  • Review scheduler configurations for bypass scenarios.
  • Test thoroughly after applying the kernel update.
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-99104.

URL Resource
https://git.kernel.org/stable/c/5bdeca322a6f8d10acaf67cccab1f69747ee7be3
https://git.kernel.org/stable/c/f0f18075e45d47bef7ff2eb9512ee4f0c7e5f9c7
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-99104 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-99104 weaknesses.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-99104 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-99104 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Oct. 28, 2026

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: sched_ext: Fix the bypass dispatch claim for schedulers bypassed by an ancestor scx_bypass() claims bypass dispatch when the scheduler's depth goes from zero to one and releases it when the depth returns to zero, but propagates only the depth to the descendants, not the claim. A descendant that starts bypassing with its ancestor never claims, and one whose own bypass ends under the ancestor's keeps its claim, as its depth does not return to zero. A sub-scheduler enable whose bypass ends under a PM suspend thus leaks its claim: the parent keeps hosting bypass dispatch and the sub-scheduler's next bypass trips the WARN_ON_ONCE() on the claim. A sub-scheduler disable that starts under a PM suspend has no claim, so once the resume lifts the root's bypass its tasks sit on the parent's bypass DSQs with nobody consuming them. Claim for every descendant whose depth goes from zero to one in the propagation and release every scheduler in the subtree whose depth returned to zero once the tasks have moved out of the bypass DSQs. A parent that is bypassing itself when a descendant claims consumes only its own bypass DSQs, empty until it leaves bypass and becomes the host.
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/99xxx/CVE-2026-99104.json">CVE-2026-99104</a>
    Added Reference https://git.kernel.org/stable/c/5bdeca322a6f8d10acaf67cccab1f69747ee7be3
    Added Reference https://git.kernel.org/stable/c/f0f18075e45d47bef7ff2eb9512ee4f0c7e5f9c7
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.