Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
usb: typec: ucsi: ccg: Fix use-after-free of ucsi on remove
The threaded IRQ handler ccg_irq_handler() calls ucsi_notify_common(), which on a connector-change event calls ucsi_connector_change() and schedules connector work. In ucsi_ccg_remove(), ucsi_destroy() frees uc->ucsi (kfree) before free_irq() is called, so a handler invocation already in flight may access the freed object after ucsi_destroy().
CPU 0 (remove) | CPU 1 (threaded IRQ) ucsi_destroy(uc->ucsi) | ccg_irq_handler() kfree(ucsi) // FREE | ucsi_notify_common(uc->ucsi) // USE
Move free_irq() before ucsi_destroy() in the remove path. It is kept after ucsi_unregister(): ucsi_unregister() cancels connector work whose handler issues GET_CONNECTOR_STATUS through ucsi_send_command_common(), which waits for a completion that is signalled from the IRQ handler, so the IRQ must stay active until that work has been cancelled.
The probe error path already orders free_irq() before ucsi_destroy().
This bug was found by static analysis.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , Debian 11 ELS , TuxCare 9.6 ESU
- Affected packages:
- kernel @ 5.10.0 (+3 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 11 | Planned | — |
| Debian 11 cloud | Planned | — |
| Debian 12 | Will Not Fix |
42 kernels
|