CVE-2025-40219 PCI/IOV: Fix race between SR-IOV enable/disable and hotplug
A race condition in the Linux kernel PCI/IOV subsystem can cause a deadlock when SR-IOV is enabled or disabled during hotplug events, leading to denial of service.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-40219?
CVE-2025-40219 is a vulnerability in Linux, published on 4 Dec 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:
PCI/IOV: Fix race between SR-IOV enable/disable and hotplug
Commit 05703271c3cd ("PCI/IOV: Add PCI rescan-remove locking when enabling/disabling SR-IOV") tried to fix a race between the VF removal inside sriov_del_vfs() and concurrent hot unplug by taking the PCI rescan/remove lock in sriov_del_vfs(). Similarly the PCI rescan/remove lock was also taken in sriov_add_vfs() to protect addition of VFs.
This approach however causes deadlock on trying to remove PFs with SR-IOV enabled because PFs disable SR-IOV during removal and this removal happens under the PCI rescan/remove lock. So the original fix had to be reverted.
Instead of taking the PCI rescan/remove lock in sriov_add_vfs() and sriov_del_vfs(), fix the race that occurs with SR-IOV enable and disable vs hotplug higher up in the callchain by taking the lock in sriov_numvfs_store() before calling into the driver's sriov_configure() callback.
Which versions are affected by CVE-2025-40219?
How do I fix CVE-2025-40219?
Apply the vendor's patch.
Is CVE-2025-40219 being exploited?
There is no known exploitation of CVE-2025-40219 in the wild and no public exploit code.
Sources
Also known as AZL-71293, BELL-CVE-2025-40219, DEBIAN-CVE-2025-40219, GHSA-p5jg-472w-q92f, ROOT-OS-UBUNTU-2404-CVE-2025-40219, UBUNTU-CVE-2025-40219.