BPF_OR Vulnerability in Linux Kernel Affecting Multiple Versions

CVE-2026-31413

What is CVE-2026-31413?

In the Linux kernel, a vulnerability in the handling of scalar values during the execution of the BPF_OR operation can result in an exploitable verification and runtime divergence. Specifically, the maybe_fork_scalars() function incorrectly processes the destination operand, allowing for potential out-of-bounds map access. The issue arises when the verifier state forks incorrectly, leading to scenarios where the constant source operand's operations do not align with expected outcomes, particularly when dealing with signed integer ranges. A fix was implemented that re-executes the appropriate instructions, ensuring accurate computation and preventing unauthorized access due to the divergence.

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