CVE-2023-53054 Information
Description
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: __dwc2_lowlevel_hw_enable -> devm_add_action_or_reset(). This adds a new devres each time. This may also happen at runtime as dwc2_lowlevel_hw_enable() can be called from udc_start().
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: … devres_log: 49000000.usb-otg ADD 82a13bba devm_action_release (8 bytes) … devres_log: 49000000.usb-otg ADD 49889daf devm_action_release (8 bytes) …
A second issue is addressed here:
- regulator_bulk_enable() is called upon each PM cycle (suspend/resume).
- regulator_bulk_disable() never gets called.
So the reference count for these regulators constantly increase by one upon each low power cycle due to missing regulator_bulk_disable() call in __dwc2_lowlevel_hw_disable().
The original fix that introduced the devm_add_action_or_reset() call fixed an issue during probe that happens due to other errors in dwc2_driver_probe() -> dwc2_core_reset(). Then the probe fails without disabling regulators when dr_mode == USB_DR_MODE_PERIPHERAL.
Rather fix the error path: disable all the low level hardware in the error path by using the \hsotg->ll_hw_enabled\ flag. Checking dr_mode has been introduced to avoid a dual call to dwc2_lowlevel_hw_disable(). \ll_hw_enabled\ should achieve the same (and is used currently in the remove() routine).
Reference
https://git.kernel.org/stable/c/1f01027c51eb16145e8e07fafea3ca07ef102d06 https://git.kernel.org/stable/c/6485fc381b6528b6f547ee1ff10bdbcbe31a6e4c https://git.kernel.org/stable/c/cba76e1fb896b573f09f51aa299223276a77bc90 https://git.kernel.org/stable/c/f747313249b74f323ddf841a9c8db14d989f296a https://git.kernel.org/stable/c/ffb8ab6f87bd28d700ab5c20d9d3a7e75067630d
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