SB2026040644 - NULL pointer dereference in Linux kernel mm
Published: April 6, 2026
Security Bulletin ID
SB2026040644
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 security vulnerability.
1) NULL pointer dereference (CVE-ID: CVE-2026-31397)
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a null pointer dereference in move_pages_huge_pmd() when handling UFFDIO_MOVE for huge zero pages. A local user can trigger the vulnerable code path to cause a denial of service.
On systems with SPARSEMEM_VMEMMAP, the flaw can instead install a PMD pointing to non-existent physical memory. The issue affects handling of huge zero page mappings in the Linux kernel memory management subsystem.
Remediation
Install update from vendor's website.