CVE-2024-26891

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

iommu/vt-d: Don't issue ATS Invalidation request when device is disconnected

For those endpoint devices connect to system via hotplug capable ports,

users could request a hot reset to the device by flapping device's link

through setting the slot's link control register, as pciehp_ist() DLLSC

interrupt sequence response, pciehp will unload the device driver and

then power it off. thus cause an IOMMU device-TLB invalidation (Intel

VT-d spec, or ATS Invalidation in PCIe spec r6.1) request for non-existence

target device to be sent and deadly loop to retry that request after ITE

fault triggered in interrupt context.

That would cause following continuous hard lockup warning and system hang

[ 4211.433662] pcieport 0000:17:01.0: pciehp: Slot(108): Link Down

[ 4211.433664] pcieport 0000:17:01.0: pciehp: Slot(108): Card not present

[ 4223.822591] NMI watchdog: Watchdog detected hard LOCKUP on cpu 144

[ 4223.822622] CPU: 144

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References