CVE-2024-35843

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

iommu/vt-d: Use device rbtree in iopf reporting path

The existing I/O page fault handler currently locates the PCI device by

calling pci_get_domain_bus_and_slot(). This function searches the list

of all PCI devices until the desired device is found. To improve lookup

efficiency, replace it with device_rbtree_find() to search the device

within the probed device rbtree.

The I/O page fault is initiated by the device, which does not have any

synchronization mechanism with the software to ensure that the device

stays in the probed device tree. Theoretically, a device could be released

by the IOMMU subsystem after device_rbtree_find() and before

iopf_get_dev_fault_param(), which would cause a use-after-free problem.

Add a mutex to synchronize the I/O page fault reporting path and the IOMMU

release device path. This lock doesn't introduce any performance overhead,

as the conflict between I/O page fault reporting and device releasing is

very rare.