CVE-2026-31691 igb: remove napi_synchronize() in igb_down()

In the Linux kernel, the following vulnerability has been resolved: igb: remove napisynchronize in igbdown When an AFXDP zero-copy application terminates abruptly e.g., kill -9, the XSK buffer pool is destroyed but NAPI polling continues. igbcleanrxirqzc repeatedly returns the full budget,...