Re: [PATCH net] xsk: fix NULL pointer dereference in __xsk_rcv()

[Cen Zhang (Microsoft)]

> ... which means they are "lost"?

You are right. The UMEM frames already consumed from the Fill Ring must
be recycled into free_list when the packet cannot be completed. 

Since the current loop calls __xsk_rcv_zc_safe(), and therefore
xp_release(), after every allocation, they cannot simply be recycled
after a later failure. I will rework v2 as a two-stage transaction:
first allocate and stage all required buffers, recycling all staged
buffers if any allocation fails; then run the error-free
copy/submit/release loop only after the allocation stage succeeds.

Thanks.