Use-after-free in Linux kernel - CVE-2026-64475
Published: July 27, 2026
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in the VGA arbiter callback handling in vfio_pci_core_register_device() when registration of a vfio PCI device fails after VGA arbiter client initialization. A local user can trigger device registration failure and leave a stale callback referencing freed device data to cause a denial of service.
The issue occurs on the error path and depends on a stale VGA arbiter registration remaining after the vfio device state has been freed.
Affected software
Ubuntu
linux (Ubuntu package)
linux-azure (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
How to mitigate CVE-2026-64475
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1011.11, 7.0.0-1014.14
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
External References
- https://git.kernel.org/stable/c/0f2a35a0c7ea7da347b814750eaa78adf3582381
- https://git.kernel.org/stable/c/278a5659c391fe5afe5f9ce1bad1fd24e90144f1
- https://git.kernel.org/stable/c/42d758a09d2c46c42357ecde9a5492f015bde2e5
- https://git.kernel.org/stable/c/52adb2dff7ce3d8430e2bdc5988b618a430def85
- https://git.kernel.org/stable/c/8d65decde9afd2bd78bcfffdc0df73b82a0b5509
- https://git.kernel.org/stable/c/9e0a3f642e607848669235f5069f35640abbfc88
- https://git.kernel.org/stable/c/daedde7f024ecf88bc8e832ed40cf2c795f0796a
- https://git.kernel.org/stable/c/ef4c38d30b3744e89eb5048218904bb629ea8d47