In the Linux kernel, the following vulnerability has been resolved: power: supply: bq256xx: drain usb_work before freeing the charger The USB-PHY… (CVE-2026-89474)
A use-after-free vulnerability in the Linux kernel's power supply driver for bq256xx was resolved. The issue involved the USB-PHY notifier queuing work that could dereference freed charger data due to improper ordering of resource release and notifier unregistration. The fix ensures proper draining of queued work before freeing resources and correct initialization order to prevent premature worker execution.
AI Analysis
Technical Summary
The vulnerability in the Linux kernel's power supply subsystem for bq256xx chargers stems from the USB-PHY notifier queuing usb_work whose handler calls power_supply_changed on a charger object. The reset devm action was registered before the power supplies, causing the charger to be freed before the notifier was unregistered and usb_work drained. This could lead to usb_work dereferencing a freed charger pointer. The fix involves registering the reset action after the power supplies to ensure notifier unregistration and draining of usb_work before releasing supplies, and initializing usb_work and obtaining PHY references before notifier registration to prevent the worker running prematurely. The issue was found via static analysis.
Potential Impact
If unpatched, queued usb_work could dereference freed memory, potentially causing kernel crashes or undefined behavior. This is a use-after-free vulnerability affecting the kernel's power supply driver for bq256xx, which could impact system stability.
Mitigation Recommendations
A fix has been implemented in the Linux kernel source code that corrects the order of resource release and notifier unregistration to prevent use-after-free. Users should update to the fixed kernel version once available. No additional mitigation is indicated.
In the Linux kernel, the following vulnerability has been resolved: power: supply: bq256xx: drain usb_work before freeing the charger The USB-PHY… (CVE-2026-89474)
Description
A use-after-free vulnerability in the Linux kernel's power supply driver for bq256xx was resolved. The issue involved the USB-PHY notifier queuing work that could dereference freed charger data due to improper ordering of resource release and notifier unregistration. The fix ensures proper draining of queued work before freeing resources and correct initialization order to prevent premature worker execution.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in the Linux kernel's power supply subsystem for bq256xx chargers stems from the USB-PHY notifier queuing usb_work whose handler calls power_supply_changed on a charger object. The reset devm action was registered before the power supplies, causing the charger to be freed before the notifier was unregistered and usb_work drained. This could lead to usb_work dereferencing a freed charger pointer. The fix involves registering the reset action after the power supplies to ensure notifier unregistration and draining of usb_work before releasing supplies, and initializing usb_work and obtaining PHY references before notifier registration to prevent the worker running prematurely. The issue was found via static analysis.
Potential Impact
If unpatched, queued usb_work could dereference freed memory, potentially causing kernel crashes or undefined behavior. This is a use-after-free vulnerability affecting the kernel's power supply driver for bq256xx, which could impact system stability.
Mitigation Recommendations
A fix has been implemented in the Linux kernel source code that corrects the order of resource release and notifier unregistration to prevent use-after-free. Users should update to the fixed kernel version once available. No additional mitigation is indicated.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-542v-8xr4-x59m
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-89474"]
Threat ID: 6aa4a02255bf5e2cf5a869a4
Added to database: 09/12/2026, 00:43:14 UTC
Last enriched: 09/12/2026, 01:16:21 UTC
Last updated: 09/12/2026, 01:16:21 UTC
Views: 2
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