SB20261022489 - Improper input validation in Linux kernel md dm-pcache driver

Description

This security bulletin contains information about 1 vulnerability.

1) Improper input validation (CVE-ID: CVE-2026-98868)

CWE-ID: CWE-20 - Improper input validation

CVSSv4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/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.

The vulnerability exists due to insufficient validation of kset sizes in the Linux kernel dm-pcache component when processing on-media cache metadata during cache replay, writeback, or garbage collection. A local privileged user can supply cache metadata with a forged key_num value, if able to modify that metadata, to make the calculated kset size exceed the remaining segment space and trigger the cache_pos_advance() BUG_ON, causing a denial of service.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/01a700e9278da5706c865b9ca3ae70fdb7b4531d
• https://git.kernel.org/stable/c/7ac1f10f987a2ffae4aecf0e2ceca8f552b665cb
• https://git.kernel.org/stable/c/96e2863b1f81ea61b8d8d5d5a45d3b4c018f8e10