CVE-2022-49219 vfio/pci: fix memory leak during D3hot to D0 transition
A memory leak in the Linux kernel's VFIO PCI driver allows attackers to cause an out-of-memory denial of service by repeatedly triggering specific power state transitions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-49219?
CVE-2022-49219 is a medium-severity denial of service vulnerability in Linux kernel, published on 26 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
vfio/pci: fix memory leak during D3hot to D0 transition
If 'vfio_pci_core_device::needs_pm_restore' is set (PCI device does not have No_Soft_Reset bit set in its PMCSR config register), then the current PCI state will be saved locally in 'vfio_pci_core_device::pm_save' during D0->D3hot transition and same will be restored back during D3hot->D0 transition. For saving the PCI state locally, pci_store_saved_state() is being used and the pci_load_and_free_saved_state() will free the allocated memory.
But for reset related IOCTLs, vfio driver calls PCI reset-related API's which will internally change the PCI power state back to D0. So, when the guest resumes, then it will get the current state as D0 and it will skip the call to vfio_pci_set_power_state() for changing the power state to D0 explicitly. In this case, the memory pointed by 'pm_save' will never be freed. In a malicious sequence, the state changing to D3hot followed by VFIO_DEVICE_RESET/VFIO_DEVICE_PCI_HOT_RESET can be run in a loop and it can cause an OOM situation.
This patch frees the earlier allocated memory first before overwriting 'pm_save' to prevent the mentioned memory leak.
Weakness: CWE-401
Which versions are affected by CVE-2022-49219?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49219?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2022-49219 being exploited?
There is no known exploitation of CVE-2022-49219 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49219, GHSA-pg5j-wj7f-h3mx, UBUNTU-CVE-2022-49219.