Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
net: seeq: Fix use after free vulnerability in ether3 Driver Due to Race Condition
In the ether3_probe function, a timer is initialized with a callback function ether3_ledoff, bound to &prev(dev)->timer. Once the timer is started, there is a risk of a race condition if the module or device is removed, triggering the ether3_remove function to perform cleanup. The sequence of operations that may lead to a UAF bug is as follows:
CPU0 CPU1
| ether3_ledoff ether3_remove | free_netdev(dev); | put_devic | kfree(dev); | | ether3_outw(priv(dev)->regs.config2 |= CFG2_CTRLO, REG_CONFIG2); | // use dev
Fix it by ensuring that the timer is canceled before proceeding with the cleanup in ether3_remove.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Oracle Linux 7 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS
- Affected packages:
- kernel-uek @ 5.4.17 (+7 more)
In the Linux kernel, the following vulnerability has been resolved:
net: seeq: Fix use after free vulnerability in ether3 Driver Due to Race Condition
In the ether3_probe function, a timer is initialized with a callback function ether3_ledoff, bound to &prev(dev)->timer. Once the timer is started, there is a risk of a race condition if the module or device is removed, triggering the ether3_remove function to perform cleanup. The sequence of operations that may lead to a UAF bug is as follows:
CPU0 CPU1
| ether3_ledoff ether3_remove | free_netdev(dev); | put_devic | kfree(dev); | | ether3_outw(priv(dev)->regs.config2 |= CFG2_CTRLO, REG_CONFIG2); | // use dev
Fix it by ensuring that the timer is canceled before proceeding with the cleanup in ether3_remove.