CVE-2021-47361 Information

Description

In the Linux kernel the following vulnerability has been resolved:

mcb: fix error handling in mcb_alloc_bus()

There are two bugs:

1. If ida_simple_get() fails then this code calls put_device(carrier) but we haven’t yet called get_device(carrier) and probably that leads to a use after free.
2. After device_initialize() then we need to use put_device() to release the bus. This will free the internal resources tied to the device and call mcb_free_bus() which will free the rest.

Reference

https://git.kernel.org/stable/c/8a558261fa57a6deefb0925ab1829f698b194aea https://git.kernel.org/stable/c/115b07d9f47e3996430b8f2007edd9768e1f807f https://git.kernel.org/stable/c/66f74ba9be9daf9c47fface6af3677f602774f6b https://git.kernel.org/stable/c/7751f609eadf36b1f53712bae430019c53a16eb0 https://git.kernel.org/stable/c/91e4ad05bf18322b5921d1a6c9b603f6eb1694f0 https://git.kernel.org/stable/c/9fc198f415dee070a1de957bb5bf5921d8df3499 https://git.kernel.org/stable/c/25a1433216489de4abc889910f744e952cb6dbae