bpf: Teach stack depth check about async callbacks.

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Teach max stack depth checking algorithm about async callbacks
that don't increase bpf program stack size.
Also add sanity check that bpf_tail_call didn't sneak into async cb.
It's impossible, since PTR_TO_CTX is not available in async cb,
hence the program cannot contain bpf_tail_call(ctx,...);

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210715005417.78572-10-alexei.starovoitov@gmail.com

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Alexei Starovoitov 2021-07-14 17:54:15 -07:00 • committed by Daniel Borkmann

parent bfc6bb74e4

commit 7ddc80a476

2 changed files with 16 additions and 3 deletions

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include/linux/bpf_verifier.h

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18

kernel/bpf/verifier.c

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