bpf/verifier: allow all functions to read user provided context

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When a function was trying to access data from context in a syscall eBPF
program, the verifier was rejecting the call unless it was accessing the
first element.
This is because the syscall context is not known at compile time, and
so we need to check this when actually accessing it.

Check for the valid memory access if there is no convert_ctx callback,
and allow such situation to happen.

Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20220906151303.2780789-4-benjamin.tissoires@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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Benjamin Tissoires 2022-09-06 17:12:59 +02:00 • committed by Alexei Starovoitov

parent 95f2f26f3c

commit 15baa55ff5

1 changed files with 19 additions and 0 deletions

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kernel/bpf/verifier.c

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