Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
uio: Fix stale info pointer in failed registration path
After device_add(), the UIO device is visible to userspace and /dev/uioX can be opened. If a later setup step fails, __uio_register_device() unwinds the device but leaves idev->info pointing at the caller-owned struct uio_info.
That is unsafe when an opener races with the failed registration path. The open file keeps a reference to the uio_device, while the caller sees registration failure and may free its struct uio_info. Later file operations can then follow idev->info and dereference freed memory.
Handle post-device_add() failures like unregister: remove UIO attributes while the info pointer is still valid, then clear idev->info under info_lock and wake existing waiters/async users before removing the device and minor. This makes already-open file descriptors observe the same “device gone” state as normal uio_unregister_device().
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+10 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| AlmaLinux 9.2 ESU | Planned | — |
| Debian 12 | Planned | — |
| Debian 13 | Planned | — |