CVE-2026-80582: drm/shmem_helper: Check VMA boundaries for PMD mappings
In the Linux kernel, the following vulnerability has been resolved:
drm/shmemhelper: Check VMA boundaries for PMD mappings
In the ->hugefault handler do not install a PMD huge page mapping if the huge page exceeds the boundaries of the VMA.
All other ->hugefault handlers have similar checks and the resulting mapping will trigger a VMBUGONVMA() if it ever reaches copypmdrange().
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1 - Compensating control
In the ->huge_fault handler, do not install a PMD huge-page mapping when the huge page exceeds the VMA boundaries.
Event History
Frequently Asked Questions
What condition leads to the unsafe PMD mapping?
The condition occurs in the drm/shmem_helper ->huge_fault handler when it installs a PMD huge-page mapping that extends beyond the boundaries of the VMA.
How can an affected system show that this condition was reached?
If the resulting mapping reaches copy_pmd_range(), it triggers a VM_BUG_ON_VMA().
What component should be prioritized for remediation?
Prioritize the Linux kernel's DRM shmem helper handling, specifically the ->huge_fault path for PMD mappings.