Integer overflow in Linux kernel - CVE-2026-31648
Published: April 25, 2026
Vulnerability details
The vulnerability allows a local user to cause memory corruption.
The vulnerability exists due to an integer overflow in filemap_map_pages() when mapping file-backed folios during a race with file size truncation. A local user can trigger the race to cause memory corruption.
The issue can cause mappings to extend beyond the large folio size and corrupt fields of pages that do not belong to that folio.
Affected software
Debian Linux
Ubuntu
linux (Ubuntu package)
linux-fips (Ubuntu package)
linux-hwe-6.8 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oracle-6.8 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-aws-6.8 (Ubuntu package)
linux-aws (Ubuntu package)
linux-azure-fde (Ubuntu package)
linux-azure-fde-6.8 (Ubuntu package)
linux-azure (Ubuntu package)
linux-azure-fips (Ubuntu package)
linux-gcp-fips (Ubuntu package)
linux (Debian package)
How to mitigate CVE-2026-31648
linux (Ubuntu package) - addressed in versions 6.8.0-136.136, 6.8.0-1046.50, 6.8.0-1059.67, 6.8.0-1064.72, 6.8.0-1064.72~22.04.1, 6.8.1-1056.57, 6.8.1-1056.57~22.04.2
linux-fips (Ubuntu package) - addressed in versions 6.8.0-136.136+fips2, 6.8.0-136.136.2, 6.8.0-136.136.2~22.04.1, 6.8.0-1058.61
linux-hwe-6.8 (Ubuntu package) - update to 6.8.0-136.136~22.04.1
linux-ibm (Ubuntu package) - addressed in versions 6.8.0-1030.31, 6.8.0-1033.34, 6.8.0-1061.62, 6.8.0-1061.62~22.04.1
linux-oracle-6.8 (Ubuntu package) - update to 6.8.0-1058.61~22.04.1
linux-nvidia (Ubuntu package) - addressed in versions 6.8.0-1059.62, 6.8.0-1059.62.1, 6.8.0-1059.62~22.04.1
linux-aws-6.8 (Ubuntu package) - addressed in versions 6.8.0-1061.64+fips1, 6.8.0-1061.64~22.04.1
linux-aws (Ubuntu package) - update to 6.8.0-1061.64+1
linux-azure-fde (Ubuntu package) - update to 6.8.0-1062.69
linux-azure-fde-6.8 (Ubuntu package) - update to 6.8.0-1062.69~22.04.1
linux-azure (Ubuntu package) - addressed in versions 6.8.0-1063.71, 6.8.0-1063.71~22.04.1
linux-azure-fips (Ubuntu package) - update to 6.8.0-1063.71+fips2
linux-gcp-fips (Ubuntu package) - update to 6.8.0-1064.72+fips1
linux (Debian package) - update to 6.12.85-1
External References
- https://git.kernel.org/stable/c/576543bedd616254032d4ebe54a90076f9e31740
- https://git.kernel.org/stable/c/633ab680c405ac390e6bec5b74aaf46197c837b6
- https://git.kernel.org/stable/c/88591194df736a508dd5461ab2167a61e98caac1
- https://git.kernel.org/stable/c/9316a820b9aae07d44469d6485376dad824c5b3f
- https://git.kernel.org/stable/c/f58df566524ebcdfa394329c64f47e3c9257516e
Related Security Bulletins
- Integer overflow in Linux kernel mm
- Debian update for linux
- Ubuntu update for linux
- Ubuntu update for linux-gcp-fips
- Ubuntu update for linux-oracle-6.8
- Ubuntu update for linux-fips
- Ubuntu update for linux-nvidia
- Ubuntu update for linux-azure-fde-6.8
- Ubuntu update for linux-azure-fips
- Ubuntu update for linux-azure-fde
- Ubuntu update for linux-azure
- Ubuntu update for linux-aws
- Ubuntu update for linux-hwe-6.8
- Ubuntu update for linux-aws-6.8
- Ubuntu update for linux-ibm