CVE-2024-58034

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

memory: tegra20-emc: fix an OF node reference bug in tegra_emc_find_node_by_ram_code()

As of_find_node_by_name() release the reference of the argument device node, tegra_emc_find_node_by_ram_code() releases some device nodes while still in use, resulting in possible UAFs. According to the bindings and the in-tree DTS files, the emc-tables node is always devices child node with the property nvidia,use-ram-code, and the lpddr2 node is a child of the emc-tables node. Thus utilize the for_each_child_of_node() macro and of_get_child_by_name() instead of of_find_node_by_name() to simplify the code.

This bug was found by an experimental verification tool that I am developing.

[krzysztof: applied v1, adjust the commit msg to incorporate v2 parts]

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/3b02273446e23961d910b50cc12528faec649fb2
• https://git.kernel.org/stable/c/755e44538c190c31de9090d8e8821d228fcfd416
• https://git.kernel.org/stable/c/b9784e5cde1f9fb83661a70e580e381ae1264d12
• https://git.kernel.org/stable/c/c144423cb07e4e227a8572d5742ca2b36ada770d
• https://git.kernel.org/stable/c/e9d07e91de140679eeaf275f47ad154467cb9e05