tree e938bd0ddcc06c32df59b527d148ffa7aab9f636
parent f2a4d086ed4c588d32fe9b7aa67fead7280e7bf1
author Daniel Borkmann <daniel@iogearbox.net> 1465586346 +0200
committer David S. Miller <davem@davemloft.net> 1465606857 -0700

bpf: enforce recursion limit on redirects

Respect the stack's xmit_recursion limit for calls into dev_queue_xmit().
Currently, they are not handeled by the limiter when attached to clsact's
egress parent, for example, and a buggy program redirecting it to the
same device again could run into stack overflow eventually. It would be
good if we could notify an admin to give him a chance to react. We reuse
xmit_recursion instead of having one private to eBPF, so that the stack's
current recursion depth will be taken into account as well. Follow-up to
commit 3896d655f4d4 ("bpf: introduce bpf_clone_redirect() helper") and
27b29f63058d ("bpf: add bpf_redirect() helper").

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>