Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_hid: don’t call cdev_init while cdev in use
When calling unbind, then bind again, cdev_init reinitialized the cdev, even though there may still be references to it. That’s the case when the /dev/hidg* device is still opened. This obviously unsafe behavior like oopes.
This fixes this by using cdev_alloc to put the cdev on the heap. That way, we can simply allocate a new one in hidg_bind.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 4.18.0 (+9 more)
In the Linux kernel, the following vulnerability has been resolved:
usb: gadget: f_hid: don’t call cdev_init while cdev in use
When calling unbind, then bind again, cdev_init reinitialized the cdev, even though there may still be references to it. That’s the case when the /dev/hidg* device is still opened. This obviously unsafe behavior like oopes.
This fixes this by using cdev_alloc to put the cdev on the heap. That way, we can simply allocate a new one in hidg_bind.