Linux 5.18 Xen USB Driver To Harden Against Malicious Hosts

The many USB and Thunderbolt feature patches have landed into the in-development Linux 5.18 kernel.

While there are many USB/Thunderbolt changes this cycle, there isn't much that is particularly notable besides continued work on the USB DWC3 driver, XHCI debug cable fixes, a Richtek rt1719 power delivery driver, and other routine updates.

One interesting bit is the Xen USB driver being hardened against potentially malicious hosts. The Xen pvUSB driver was mainlined in Linux 5.17 after being out-of-tree for more than one decade.

But it turns out this new Xen USB driver was missing some verification/sanitization of data around I/O length, interrupt storms, and other missing safeguards. With Linux 5.18 this xen_hcd driver is now hardened against malicious backends/hosts from infiltrating the kernel through this driver's missing checks/safeguards.

The full list of USB/Thunderbolt changes for Linux 5.18 can be found via Greg KH's pull request that was already merged to mainline.