SB20261023183 - Memory leak in Linux kernel fs

Description

This security bulletin contains information about 1 vulnerability.

1) Memory leak (CVE-ID: CVE-2026-98989)

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

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 exhaust kernel memory and cause a denial of service.

The vulnerability exists due to insufficient checks for mount namespace reference cycles in do_loopback() in fs/namespace.c when recursively bind-mounting a source from another mount namespace. A local user can stack mount namespace file descriptors from an older mount namespace and repeatedly perform recursive bind mounts to create self-referencing namespaces, leaking the namespaces and their mounts until memory is exhausted.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/37a82f400efa4d263542a5fa41755b21057f1e5d
• https://git.kernel.org/stable/c/a0ba48256f5dff6f75a45f8ce39fe57f21df1022
• https://git.kernel.org/stable/c/c640a01a78e42302879006ed7b7d5a9a943ba815