SB20261029214 - Improper control of a resource through its lifetime in Linux kernel sched ext

Description

This security bulletin contains information about 1 vulnerability.

1) Improper control of a resource through its lifetime (CVE-ID: CVE-2026-99104)

CWE-ID: CWE-664 - Improper control of a resource through its lifetime

CVSSv4: 5.6 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local privileged user to cause a denial of service by leaving affected tasks unable to run.

The vulnerability exists due to improper management of bypass dispatch claims in the Linux kernel sched_ext scx_bypass() function when propagating bypass state to descendant schedulers. A local privileged user can potentially trigger sub-scheduler enable or disable operations overlapping power-management suspend to leave tasks queued on bypass dispatch queues without a scheduler consuming them, causing a denial of service.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/5bdeca322a6f8d10acaf67cccab1f69747ee7be3
• https://git.kernel.org/stable/c/f0f18075e45d47bef7ff2eb9512ee4f0c7e5f9c7