CVE-2024-58002

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

media: uvcvideo: Remove dangling pointers

When an async control is written, we copy a pointer to the file handle that started the operation. That pointer will be used when the device is done. Which could be anytime in the future.

If the user closes that file descriptor, its structure will be freed, and there will be one dangling pointer per pending async control, that the driver will try to use.

Clean all the dangling pointers during release().

To avoid adding a performance penalty in the most common case (no async operation), a counter has been introduced with some logic to make sure that it is properly handled.

Weakness

Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code.

Affected Software

Extended Description

The use of previously-freed memory can have any number of adverse consequences, ranging from the corruption of valid data to the execution of arbitrary code, depending on the instantiation and timing of the flaw. The simplest way data corruption may occur involves the system’s reuse of the freed memory. Use-after-free errors have two common and sometimes overlapping causes:

In this scenario, the memory in question is allocated to another pointer validly at some point after it has been freed. The original pointer to the freed memory is used again and points to somewhere within the new allocation. As the data is changed, it corrupts the validly used memory; this induces undefined behavior in the process. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.

Potential Mitigations

References

• https://git.kernel.org/stable/c/221cd51efe4565501a3dbf04cc011b537dcce7fb
• https://git.kernel.org/stable/c/438bda062b2c40ddd7df23b932e29ffe0a448cac
• https://git.kernel.org/stable/c/4dbaa738c583a0e947803c69e8996e88cf98d971
• https://git.kernel.org/stable/c/9edc7d25f7e49c33a1ce7a5ffadea2222065516c
• https://git.kernel.org/stable/c/ac18d781466252cd35a3e311e0a4b264260fd927