CVE-2022-50879: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-50879 is a NULL pointer dereference vulnerability in the Linux kernel's objtool component. The flaw occurs because find_insn() can return NULL on failure, and the return value was not checked before use, leading to a kernel NULL pointer dereference (Oops/SEGFAULT). It affects Linux kernel versions from the initial commit up to the fixes introduced in stable releases 5.4.229, 5.10.163, 5.15.87, 6.0.17, 6.1.3, and 6.2. The CVE was published on December 30, 2025, with an EPSS score of approximately 0.024% (very low), and no CVSS base score has been assigned (Feedly, ENISA EUVD).

The root cause is a missing NULL pointer check (CWE-476: NULL Pointer Dereference) in the Linux kernel's objtool static analysis tool. Specifically, find_insn() returns NULL when it cannot locate an instruction, and the calling code failed to validate this return value before dereferencing the pointer, resulting in a kernel Oops. The fix adds a NULL check on the insn variable returned by find_insn() before it is used. Patches were applied across multiple stable kernel branches (Feedly, ENISA EUVD).

Exploitation of this vulnerability could cause a kernel NULL pointer dereference, resulting in a system crash (denial of service). Since objtool is a build-time and kernel analysis tool rather than a runtime attack surface exposed to unprivileged users, the practical impact is primarily limited to availability — specifically, triggering a kernel Oops that may crash or destabilize the affected system. There is no known confidentiality or integrity impact, and no evidence of lateral movement potential associated with this flaw (Feedly).

Update the Linux kernel to a patched stable version: 5.4.229, 5.10.163, 5.15.87, 6.0.17, 6.1.3, or 6.2 (or later). Distributions based on these stable branches should apply the relevant vendor kernel updates. No configuration-based workaround is known; upgrading to a fixed kernel version is the recommended remediation (ENISA EUVD, Feedly).