CVE-2023-52510

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

ieee802154: ca8210: Fix a potential UAF in ca8210_probe

If of_clk_add_provider() fails in ca8210_register_ext_clock(), it calls clk_unregister() to release priv->clk and returns an error. However, the caller ca8210_probe() then calls ca8210_remove(), where priv->clk is freed again in ca8210_unregister_ext_clock(). In this case, a use-after-free may happen in the second time we call clk_unregister().

Fix this by removing the first clk_unregister(). Also, priv->clk could be an error code on failure of clk_register_fixed_rate(). Use IS_ERR_OR_NULL to catch this case in ca8210_unregister_ext_clock().

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/217efe32a45249eb07dcd7197e8403de98345e66
• https://git.kernel.org/stable/c/28b68cba378e3e50a4082b65f262bc4f2c7c2add
• https://git.kernel.org/stable/c/55e06850c7894f00d41b767c5f5665459f83f58f
• https://git.kernel.org/stable/c/84c6aa0ae5c4dc121f9996bb8fed46c80909d80e
• https://git.kernel.org/stable/c/85c2857ef90041f567ce98722c1c342c4d31f4bc
• https://git.kernel.org/stable/c/becf5c147198f4345243c5df0c4f035415491640
• https://git.kernel.org/stable/c/cdb46be93c1f7bbf2c4649e9fc5fb147cfb5245d
• https://git.kernel.org/stable/c/f990874b1c98fe8e57ee9385669f501822979258
• https://git.kernel.org/stable/c/217efe32a45249eb07dcd7197e8403de98345e66
• https://git.kernel.org/stable/c/28b68cba378e3e50a4082b65f262bc4f2c7c2add
• https://git.kernel.org/stable/c/55e06850c7894f00d41b767c5f5665459f83f58f
• https://git.kernel.org/stable/c/84c6aa0ae5c4dc121f9996bb8fed46c80909d80e
• https://git.kernel.org/stable/c/85c2857ef90041f567ce98722c1c342c4d31f4bc
• https://git.kernel.org/stable/c/becf5c147198f4345243c5df0c4f035415491640
• https://git.kernel.org/stable/c/cdb46be93c1f7bbf2c4649e9fc5fb147cfb5245d
• https://git.kernel.org/stable/c/f990874b1c98fe8e57ee9385669f501822979258