Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
um: Add winch to winch_handlers before registering winch IRQ
Registering a winch IRQ is racy, an interrupt may occur before the winch is added to the winch_handlers list.
If that happens, register_winch_irq() adds to that list a winch that is scheduled to be (or has already been) freed, causing a panic later in winch_cleanup().
Avoid the race by adding the winch to the winch_handlers list before registering the IRQ, and rolling back if um_request_irq() fails.
Details
- Affected product:
- Oracle Linux 7 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS
- Affected packages:
- linux-hwe @ 4.15.0 (+3 more)
In the Linux kernel, the following vulnerability has been resolved:
um: Add winch to winch_handlers before registering winch IRQ
Registering a winch IRQ is racy, an interrupt may occur before the winch is added to the winch_handlers list.
If that happens, register_winch_irq() adds to that list a winch that is scheduled to be (or has already been) freed, causing a panic later in winch_cleanup().
Avoid the race by adding the winch to the winch_handlers list before registering the IRQ, and rolling back if um_request_irq() fails.