Re: [PATCH 2/3] powerpc: bpf: flush the entire JIT buffer
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2017-01-13 23:16:19
Also in:
netdev
From: Daniel Borkmann <daniel@iogearbox.net>
Date: 2017-01-13 23:16:19
Also in:
netdev
On 01/13/2017 06:10 PM, Naveen N. Rao wrote:
With bpf_jit_binary_alloc(), we allocate at a page granularity and fill the rest of the space with illegal instructions to mitigate BPF spraying attacks, while having the actual JIT'ed BPF program at a random location within the allocated space. Under this scenario, it would be better to flush the entire allocated buffer rather than just the part containing the actual program. We already flush the buffer from start to the end of the BPF program. Extend this to include the illegal instructions after the BPF program. Signed-off-by: Naveen N. Rao <redacted>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>