CVE-2023-53054

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

usb: dwc2: fix a devres leak in hw_enable upon suspend resume

Each time the platform goes to low power, PM suspend / resume routines call: _dwc2lowlevelhwenable -> devmaddactionorreset(). This adds a new devres each time. This may also happen at runtime, as dwc2lowlevelhwenable() can be called from udcstart().

This can be seen with tracing: - echo 1 > /sys/kernel/debug/tracing/events/dev/devres_log/enable - go to low power - cat /sys/kernel/debug/tracing/trace

A new "ADD" entry is found upon each low power cycle: ... devreslog: 49000000.usb-otg ADD 82a13bba devmactionrelease (8 bytes) ... devreslog: 49000000.usb-otg ADD 49889daf devmactionrelease (8 bytes) ...

A second issue is addressed here: - regulatorbulkenable() is called upon each PM cycle (suspend/resume). - regulatorbulkdisable() never gets called.

So the reference count for these regulators constantly increase, by one upon each low power cycle, due to missing regulatorbulkdisable() call in _dwc2lowlevelhwdisable().

The original fix that introduced the devmaddactionorreset() call, fixed an issue during probe, that happens due to other errors in dwc2driverprobe() -> dwc2corereset(). Then the probe fails without disabling regulators, when drmode == USBDRMODEPERIPHERAL.

Rather fix the error path: disable all the low level hardware in the error path, by using the "hsotg->llhwenabled" flag. Checking drmode has been introduced to avoid a dual call to dwc2lowlevelhwdisable(). "llhwenabled" should achieve the same (and is used currently in the remove() routine).