Improper input validation in Linux kernel - CVE-2026-31458
Published: April 24, 2026
Vulnerability details
The vulnerability allows a local privileged user to cause a denial of service.
The vulnerability exists due to improper input validation in damon_sysfs_handle_cmd() when handling sysfs commands after nr_contexts is set to 0. A local privileged user can write crafted values to sysfs control files to cause a denial of service.
The issue is triggered while DAMON is running, and commands other than OFF can dereference contexts_arr[0] after the contexts directory is made empty.
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-2026-31458
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/1bfe9fb5ed2667fb075682408b776b5273162615
- https://git.kernel.org/stable/c/1e8da792672481d603fa7cd0d815577220a3ee27
- https://git.kernel.org/stable/c/708033c231bd782858f4ddbb46ee874a5a5fbdab
- https://git.kernel.org/stable/c/aba546061341b56e9ffb37e1eb661a3628b6ec12
- https://git.kernel.org/stable/c/bbe03ad3fb9e714191757ca7b41582f930be7be2
Related Security Bulletins
- Improper input validation in Linux kernel damon
- 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