Fixed
Created: Nov 12, 2025
Updated: Nov 25, 2025
Resolved Date: Nov 24, 2025
Found In Version: 10.25.33.1
Fix Version: 10.25.33.3
Severity: Standard
Applicable for: Wind River Linux LTS 25
Component/s: Kernel
In the Linux kernel, the following vulnerability has been resolved:[EOL][EOL]net: usb: asix: hold PM usage ref to avoid PM/MDIO + RTNL deadlock[EOL][EOL]Prevent USB runtime PM (autosuspend) for AX88772* in bind.[EOL][EOL]usbnet enables runtime PM (autosuspend) by default, so disabling it via[EOL]the usb_driver flag is ineffective. On AX88772B, autosuspend shows no[EOL]measurable power saving with current driver (no link partner, admin[EOL]up/down). The ~0.453 W -> ~0.248 W drop on v6.1 comes from phylib powering[EOL]the PHY off on admin-down, not from USB autosuspend.[EOL][EOL]The real hazard is that with runtime PM enabled, ndo_open() (under RTNL)[EOL]may synchronously trigger autoresume (usb_autopm_get_interface()) into[EOL]asix_resume() while the USB PM lock is held. Resume paths then invoke[EOL]phylink/phylib and MDIO, which also expect RTNL, leading to possible[EOL]deadlocks or PM lock vs MDIO wake issues.[EOL][EOL]To avoid this, keep the device runtime-PM active by taking a usage[EOL]reference in ax88772_bind() and dropping it in unbind(). A non-zero PM[EOL]usage count blocks runtime suspend regardless of userspace policy[EOL](.../power/control - pm_runtime_allow/forbid), making this approach[EOL]robust against sysfs overrides.[EOL][EOL]Holding a runtime-PM usage ref does not affect system-wide suspend;[EOL]system sleep/resume callbacks continue to run as before.
