CVE-2026-97991

A flaw was found in the Linux kernel's vDPA (vHost Data Path Acceleration) block simulator driver. Due to improper input validation, the driver logs out-of-range starting sector requests but fails to reject them, causing an arithmetic underflow and an invalid buffer offset. An attacker with access to the simulated device, such as a guest virtual machine, can submit a crafted storage request to trigger out-of-bounds memory reads and writes in the host kernel. This flaw may result in a system crash leading to a denial of service, information disclosure, or arbitrary code execution.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Prevent the vdpa_sim_blk kernel module from loading by adding a modprobe configuration entry:

1. Disable loading of the module:

echo "install vdpa_sim_blk /bin/true" > /etc/modprobe.d/disable-vdpa_sim_blk.conf

2. Unload the module if it is currently loaded:

modprobe -r vdpa_sim_blk

Caveat: Disabling this module prevents creating or operating simulated vDPA block devices. Warning: If the module is actively in use by virtual machines or system processes, it cannot be safely unloaded at runtime; a system restart is required for the configuration to take effect.