usb: dwc2: fix a devres leak in hw_enable upon suspend resume
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 4.5, 4.10, 4.15, 4.20, 5.5, and 2 more
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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).
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 4.4.233 · fixed in 4.5; From 4.9.233 · fixed in 4.10; From 4.14.194 · fixed in 4.15; From 4.19.140 · fixed in 4.20; From 5.4.59 · fixed in 5.5; From 5.7.16 · fixed in 5.8; From 5.8.2 · fixed in 5.9
- Linux Linux
5.9