In the Linux kernel, the following vulnerability has been resolved:

igc: remove napi synchronize() in igc down()

When an AF XDP zero-copy application is killed abruptly, the XSK pool is torn down but NAPI keeps polling. igc clean rx irq zc() then returns the full budget on every poll, so napi complete done() never clears NAPI STATE SCHED.

igc down() calls napi synchronize() before napi disable(), so it spins forever waiting for that bit and the interface never goes down. Drop the napi synchronize() and let napi disable() do the job -- it sets NAPI STATE DISABLE, which forces the stuck poll to complete. Reorder it ahead of igc set queue napi() so the NAPI mapping is cleared only after polling has stopped, matching the recent igb fix b1e067240379.