SB20261022436 - Improper initialization in Linux kernel block

Description

This security bulletin contains information about 1 vulnerability.

1) Improper initialization (CVE-ID: CVE-2026-98820)

CWE-ID: CWE-665 - Improper Initialization

CVSSv4: 6.8 [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]

The vulnerability allows a local user to cause a denial of service by stalling a block I/O queue.

The vulnerability exists due to incorrect initialization of the RQF_USE_SCHED flag in the Linux kernel blk-mq subsystem when cached requests allocated for passthrough commands are reused for read/write operations. A local user can trigger this request reuse to bypass the prepare_request() and finish_request() scheduler callbacks, leaking domain tokens and stalling the queue when the kyber scheduler is used.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/2c47ebc27fa72078e26177cd458cdaf3006a9685
• https://git.kernel.org/stable/c/790730e4d95de8356a573d4b4864486bba731863
• https://git.kernel.org/stable/c/ab6c756f28c741d704a7c3e04814bfc3adf6f818