CVE-2022-50879 in Linux
Summary
by MITRE • 12/30/2025
In the Linux kernel, the following vulnerability has been resolved:
objtool: Fix SEGFAULT
find_insn() will return NULL in case of failure. Check insn in order to avoid a kernel Oops for NULL pointer dereference.
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Analysis
by VulDB Data Team • 04/26/2026
The vulnerability identified as CVE-2022-50879 resides within the Linux kernel's objtool utility, which serves as a critical component for validating kernel object files and ensuring proper instruction flow analysis during kernel compilation. This flaw represents a classic null pointer dereference issue that could lead to system instability and potential privilege escalation opportunities. The vulnerability specifically impacts the find_insn() function within objtool's codebase, where the function is designed to locate specific instructions within kernel object files but fails to properly validate its return values before subsequent operations.
The technical implementation of this vulnerability stems from the objtool utility's failure to perform proper null pointer validation when processing instruction data structures. When find_insn() encounters a condition that prevents it from locating a target instruction, it appropriately returns NULL to indicate failure. However, the calling code does not check this return value before attempting to dereference the pointer, creating a scenario where a null pointer dereference occurs. This type of error falls under the common CWE-476 weakness category, specifically representing a NULL pointer dereference that can lead to system crashes and potential exploitation. The kernel's objtool utility operates during the kernel build process, making this vulnerability particularly concerning as it can compromise the integrity of kernel compilation and potentially allow for the injection of malicious code into the kernel image.
The operational impact of CVE-2022-50879 extends beyond simple system crashes, as it represents a potential vector for privilege escalation attacks within kernel development environments. When exploited, this vulnerability can cause kernel Oops messages and system panics during kernel compilation, effectively preventing successful kernel builds and potentially allowing attackers with access to kernel development systems to gain elevated privileges. The vulnerability is particularly dangerous in environments where kernel modifications are frequently compiled, as it can be triggered during routine development activities. According to ATT&CK framework category T1068, this vulnerability could enable privilege escalation by allowing an attacker to manipulate kernel compilation processes. The impact is significant for kernel developers and system administrators who rely on stable compilation environments, as it can disrupt development workflows and potentially allow for the introduction of malicious code into kernel components.
Mitigation strategies for CVE-2022-50879 focus primarily on applying the official kernel patches that implement proper null pointer validation in the objtool utility. The fix requires checking the return value of find_insn() before attempting to dereference the instruction pointer, ensuring that the code gracefully handles cases where instruction lookup fails. System administrators should prioritize updating their kernel development environments to versions containing the patched objtool utility, as this vulnerability specifically affects the kernel build process rather than runtime operations. Additionally, organizations should implement proper code review processes for kernel modifications to prevent similar issues from emerging in other components of the kernel build system. The fix aligns with security best practices outlined in the CWE guidelines for preventing null pointer dereference vulnerabilities and represents a straightforward defensive measure that requires minimal system resources while providing significant protection against potential exploitation.