SB2026091702 - NULL pointer dereference in Linux kernel s390 crypto driver
Published: September 17, 2026
Security Bulletin ID
SB2026091702
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) NULL pointer dereference (CVE-ID: CVE-2026-89958)
CWE-ID: CWE-476 - NULL Pointer Dereference
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 cause a denial of service.
The vulnerability exists due to a null pointer dereference in the s390/vfio-ap AP bus configuration callbacks when handling AP bus configuration changes while matrix_mdev->kvm is unset. A local user can trigger the AP bus configuration callbacks to cause a denial of service.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/178ea7a1c2c3c0c01d14b8f60aa35f1e0cdc6b78
- https://git.kernel.org/stable/c/334b435b951353f934d5110c4630e0cb58d2f9a7
- https://git.kernel.org/stable/c/4f7e869d0db24ae07b4c888fd3bc21554eef775d
- https://git.kernel.org/stable/c/5e932abfcce6189d067fffb0eb8214443bc04374
- https://git.kernel.org/stable/c/d50346801b4f144e42b49cd4f1496010498ab114