SB2026091806 - Out-of-bounds write in Linux kernel md dm-pcache driver

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds write (CVE-ID: CVE-2026-93201)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local privileged user to perform out-of-bounds reads and writes.

The vulnerability exists due to an out-of-bounds read and write in dm-pcache cache metadata decoders and workers when processing attacker-controlled cache-device metadata. A local privileged user can supply a cache device containing an out-of-range segment identifier during a table load to perform out-of-bounds reads and writes.

The affected metadata is protected only by a CRC with a fixed public seed.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/90c990a68460d7b5720e5634cf650eccdf0f4098
• https://git.kernel.org/stable/c/b4bf8af5e7d7db4c5e179e15017da55857761ac4