SB20261022488 - 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-2026-98867)

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 corrupt kernel memory, potentially causing a denial of service.

The vulnerability exists due to an out-of-bounds write in the Linux kernel dm-pcache component when replaying persistent cache keys with unchecked logical offsets. A local privileged user can supply a malformed key through controlled cache-device metadata to cause get_subtree() to form a pointer outside req_key_tree->subtrees[], which rb_insert() subsequently writes through.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/10449703200076980704894c3d68d6796182371b
• https://git.kernel.org/stable/c/3d5a87cb909c1f375f08065b20123fa5db5958d8
• https://git.kernel.org/stable/c/97fc4b53dbe4a983fdf093243067fa6a64562307