CVE-2024-35836

In the Linux kernel, the following vulnerability has been resolved:

dpll: fix pin dump crash for rebound module

When a kernel module is unbound but the pin resources were not entirely freed (other kernel module instance of the same PCI device have had kept the reference to that pin), and kernel module is again bound, the pin properties would not be updated (the properties are only assigned when memory for the pin is allocated), prop pointer still points to the kernel module memory of the kernel module which was deallocated on the unbind.

If the pin dump is invoked in this state, the result is a kernel crash. Prevent the crash by storing persistent pin properties in dpll subsystem, copy the content from the kernel module when pin is allocated, instead of using memory of the kernel module.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/5050a5b9d8b4d3c6f7e376e07670e437db7ccf9c
• https://git.kernel.org/stable/c/830ead5fb0c5855ce4d70ba2ed4a673b5f1e7d9b
• https://git.kernel.org/stable/c/5050a5b9d8b4d3c6f7e376e07670e437db7ccf9c
• https://git.kernel.org/stable/c/830ead5fb0c5855ce4d70ba2ed4a673b5f1e7d9b