Hello, I’ve encountered an issue when using BPF_PROG_TEST_RUN and capturing the output. The kernel copies data into user space without checking the length of the destination buffer.
In bpf_test_finish(), size is the amount of data in the XDP buffer / skb after the program is run. This can be larger than data_size_in due to bpf_xdp_adjust_head() and friends. bpf_test_finish doesn’t clamp size to data_size_out, which is what I was expecting. What is the correct way to use this interface? Best, Lorenz -- Lorenz Bauer | Systems Engineer 25 Lavington St., London SE1 0NZ www.cloudflare.com