Privilege Escalation Vulnerability in Linux Kernel Affecting Non-SMP Builds

CVE-2026-90046

What is CVE-2026-90046?

The vulnerability in the Linux Kernel arises from the improper use of spin_trylock() in non-maskable interrupts (NMI) on uniprocessor (UP) systems. This issue can potentially lead to kernel crashes, particularly when BPF (Berkeley Packet Filter) programs that utilize these features are executed. Local attackers might exploit this vulnerability, enabling privilege escalation and allowing unauthorized access to system resources. The issue primarily affects non-SMP (Symmetric Multiprocessing) builds and has been recognized during code reviews without evidence of impact on real-world users.

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