CVE-2025-37946 s390/pci: Fix duplicate pci_dev_put() in disable_slot() when PF has child VFs
A double free in the s390 PCI subsystem can lead to a use-after-free, potentially allowing local attackers to execute code or escalate privileges.
- 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-2025-37946?
CVE-2025-37946 is a high-severity use after free vulnerability in Linux kernel, published on 20 May 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:
s390/pci: Fix duplicate pci_dev_put() in disable_slot() when PF has child VFs
With commit bcb5d6c76903 ("s390/pci: introduce lock to synchronize state of zpci_dev's") the code to ignore power off of a PF that has child VFs was changed from a direct return to a goto to the unlock and pci_dev_put() section. The change however left the existing pci_dev_put() untouched resulting in a doubple put. This can subsequently cause a use after free if the struct pci_dev is released in an unexpected state. Fix this by removing the extra pci_dev_put().
Weakness: CWE-416
Which versions are affected by CVE-2025-37946?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-37946?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2025-37946 being exploited?
There is no known exploitation of CVE-2025-37946 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-37946, DEBIAN-CVE-2025-37946, GHSA-f357-m44q-68mm, UBUNTU-CVE-2025-37946.