Linux Kernel ftrace Use-After-Free Vulnerability in Kprobe Registration

A use-after-free vulnerability has been identified in the Linux kernel's ftrace functionality, specifically within the kprobe registration process. This issue arises in the 'lookup_rec' function, where an invalid memory access occurs when the index is zero. The Kernel Address Sanitizer (KASAN) reported this problem, indicating a read of size 8 from a freed memory address. The vulnerability can be triggered by the 'modprobe' task, as part of the normal operation of loading kernel modules.

Impact

Exploitation of this vulnerability leads to a use-after-free condition, which can potentially be exploited to execute arbitrary code or cause a denial-of-service by crashing the system.