Re: [PATCH v16 00/12] bpf: Add kfuncs for PKCS#7 signature verification

[Kumar Kartikeya Dwivedi]

On Mon, 5 Sept 2022 at 16:34, Roberto Sassu
<roberto.sassu@xxxxxxxxxxxxxxx> wrote:
>
> From: Roberto Sassu <roberto.sassu@xxxxxxxxxx>
>
> One of the desirable features in security is the ability to restrict import
> of data to a given system based on data authenticity. If data import can be
> restricted, it would be possible to enforce a system-wide policy based on
> the signing keys the system owner trusts.
>
> This feature is widely used in the kernel. For example, if the restriction
> is enabled, kernel modules can be plugged in only if they are signed with a
> key whose public part is in the primary or secondary keyring.
>
> For eBPF, it can be useful as well. For example, it might be useful to
> authenticate data an eBPF program makes security decisions on.
>
> [...]

CI is crashing with NULL deref for test_progs-no_alu32 with llvm-16,
but I don't think the problem is in this series. This is most likely
unrelated to BPF, as the crash happens inside
kernel/time/tick-sched.c:tick_nohz_restart_sched_tick.

This was the same case in
https://lore.kernel.org/bpf/CAP01T74steDfP6O8QOshoto3e3RnHhKtAeTbnrPBZS3YJXjvbA@xxxxxxxxxxxxxx.

So, https://github.com/kernel-patches/bpf/runs/8194263557?check_suite_focus=true
and https://github.com/kernel-patches/bpf/runs/7982907380?check_suite_focus=true

look similar to me, and may not be related to BPF. They only trigger
during runs compiled using LLVM 16, so maybe some compiler
transformation is surfacing the problem?