CVE-2026-43475

A flaw was found in the Linux kernel's hv_storvsc component. When the kernel is configured with PREEMPT_RT (Real-Time Preemption) and running on a Hyper-V virtual machine, a local process performing specific I/O operations can trigger a concurrency issue. This can lead to a system lock-up or crash, resulting in a denial of service.

A Moderate impact denial of service flaw was identified in the Linux kernel's hv_storvsc component. This issue affects Red Hat Enterprise Linux systems when running a kernel configured with Real-Time Preemption (PREEMPT_RT) as a guest on a Hyper-V virtual machine. A local attacker could exploit a concurrency issue by performing specific I/O operations, leading to a system lock-up or crash.

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.

To mitigate this issue, prevent the hv_storvsc kernel module from loading. This can be achieved by creating a blacklist rule. Note that this may impact functionality if Hyper-V storage is required. A system reboot is required for the change to take effect.

Create a file named /etc/modprobe.d/blacklist-hv_storvsc.conf with the following content: blacklist hv_storvsc

Then, regenerate the initramfs: dracut -f -v

Finally, reboot the system: reboot