[PATCH 2/3] powerpc: bpf: flush the entire JIT buffer

Daniel Borkmann daniel at iogearbox.net
Sat Jan 14 09:55:00 AEDT 2017


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 <naveen.n.rao at linux.vnet.ibm.com>

Acked-by: Daniel Borkmann <daniel at iogearbox.net>


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