CVE-2025-38623 PCI: pnv_php: Fix surprise plug detection and recovery

What is CVE-2025-38623?

CVE-2025-38623 is a medium-severity denial of service vulnerability in Debian Debian Linux, published on 22 Aug 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: pnv_php: Fix surprise plug detection and recovery

The existing PowerNV hotplug code did not handle surprise plug events correctly, leading to a complete failure of the hotplug system after device removal and a required reboot to detect new devices.

This comes down to two issues:

1) When a device is surprise removed, often the bridge upstream port will cause a PE freeze on the PHB. If this freeze is not cleared, the MSI interrupts from the bridge hotplug notification logic will not be received by the kernel, stalling all plug events on all slots associated with the PE.

2) When a device is removed from a slot, regardless of surprise or programmatic removal, the associated PHB/PE ls left frozen. If this freeze is not cleared via a fundamental reset, skiboot is unable to clear the freeze and cannot retrain / rescan the slot. This also requires a reboot to clear the freeze and redetect the device in the slot.

Issue the appropriate unfreeze and rescan commands on hotplug events, and don't oops on hotplug if pci_bus_to_OF_node() returns NULL.

[bhelgaas: tidy comments]

Which versions are affected by CVE-2025-38623?

It affects 2 products.

Products include Debian Debian Linux, Linux kernel.

How do I fix CVE-2025-38623?

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-2025-38623 being exploited?

There is no known exploitation of CVE-2025-38623 in the wild and no public exploit code.

Other vulnerabilities in Debian Debian Linux

• CVE-2015-3306 ProFTPD Improper Access Control Exploited Critical 10.0
• CVE-2025-49113 RoundCube Webmail Deserialization of Untrusted Data Exploited Critical 9.9
• CVE-2026-24061 GNU InetUtils Argument Injection Exploited Critical 9.8
• CVE-2025-39682 Linux Kernel Improper Check for Unusual or Exceptional Conditions Exploited Critical 9.8
• CVE-2024-9680 Mozilla Firefox Use-After-Free Exploited Critical 9.8

All Debian Debian Linux vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as AZL-66629, BELL-CVE-2025-38623, DEBIAN-CVE-2025-38623, GHSA-jm3q-7w4m-jc2w, ROOT-OS-DEBIAN-11-CVE-2025-38623, ROOT-OS-DEBIAN-12-CVE-2025-38623 and 4 more.