SB20260625207 - Improper Initialization in Linux kernel sched

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Initialization (CVE-ID: CVE-2026-52980)

CWE-ID: CWE-665 - Improper Initialization

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper initialization in the fair scheduler sched_entity state in __sched_fork() when handling a newly forked task that later calls sched_yield(). A local user can fork a task and trigger sched_yield() to cause a denial of service.

The issue can corrupt cfs_rq->sum_w_vruntime, break EEVDF eligibility calculation, and lead to a later NULL dereference.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/3da56dc063cd77b9c0b40add930767fab4e389f3
• https://git.kernel.org/stable/c/8f4a16200785f49cf02c5b71bdfe7a9dab63f23a
• https://git.kernel.org/stable/c/c71bf35caba12bfd9bc23e32b0bcd9e02d1cf1ac
• https://git.kernel.org/stable/c/f3c16e1f4a314a20717ab90a41885f8111a242ab