SB20260828140 - Improper locking in Linux kernel iommu iommufd driver
Published: August 28, 2026
Security Bulletin ID
SB20260828140
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) Improper locking (CVE-ID: CVE-2026-80633)
CWE-ID: CWE-667 - Improper Locking
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 improper locking in iopt_release_pages() when releasing the last reference on a DMABUF-backed iopt_pages during iommufd_ioas_destroy() or iommufd_ioas_unmap(). A local user can trigger these operations to cause a denial of service.
The issue triggers a kernel WARN when dma_buf_unpin() is called without holding the exporter's dma_resv lock.
Remediation
Install update from vendor's website.