SB2026091740 - Memory leak in Linux kernel s390 kvm
Published: September 17, 2026
Security Bulletin ID
SB2026091740
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Partial DoS
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Memory leak (CVE-ID: CVE-2026-89923)
CWE-ID: CWE-401 - Missing release of memory after effective lifetime
CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a memory leak in KVM s390 vCPU destruction when destroying a vCPU while hardware breakpoints remain armed. A local user can destroy a vCPU with armed hardware breakpoints to cause a denial of service.
The leaked allocations are charged to memory cgroups and can pin dying memory cgroups.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/053f2068cf9b0654b651fed5ad7649d3deb982bf
- https://git.kernel.org/stable/c/544a5a665019cef394ce8bda97fa7a2cab253781
- https://git.kernel.org/stable/c/6c996b12bbe4a6023076e8eee3cfaf2cc99db76c
- https://git.kernel.org/stable/c/9a32c4c6a6c23b7f5bf765eb5b83ba7f64a8ec63
- https://git.kernel.org/stable/c/b5acacfdb8966abff91836c1c5bd7da59d8a526e
- https://git.kernel.org/stable/c/d6280fc540d8f4653c9b54a78cb747e128070f5e
- https://git.kernel.org/stable/c/e4d8b7f176b976474e0800ba71ee2dfa3ce263c9
- https://git.kernel.org/stable/c/e7f698b09d4a7c36b299acf680fc50fe868e2bcd