SB2026090555 - Incorrect calculation in Linux kernel mm
Published: September 5, 2026
Security Bulletin ID
SB2026090555
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Local access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Incorrect calculation (CVE-ID: CVE-2026-80893)
CWE-ID: CWE-682 - Incorrect Calculation
CVSSv4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a local user to corrupt swap entry data.
The vulnerability exists due to improper handling of userfaultfd write-protection bits in copy_hugetlb_page_range() in mm/hugetlb.c when forking a process while a hugetlb migration entry is in flight or a hugetlb page is poisoned. A local user can fork a process under these conditions to corrupt swap entry data.
Userfaultfd does not need to be involved.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/2b9a07002c2f296aa6a9c591213933d3492e3089
- https://git.kernel.org/stable/c/2fa11c60c9c06bafc19cf4d9efdaa36a38079e87
- https://git.kernel.org/stable/c/69cb5825d9988c7944bc9f1dc08cb233655405a7
- https://git.kernel.org/stable/c/83abe2fd5b3aeb3123b5408a5a91709c5538fb23
- https://git.kernel.org/stable/c/8b0de7005b148738d79d6c45594d566489948a68
- https://git.kernel.org/stable/c/f1b1311c0352873137768bac5a126e491271a747