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

[Roberto Sassu]

On Mon, 2022-09-05 at 21:26 +0200, Kumar Kartikeya Dwivedi wrote:
> 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?

Yes, I saw that too. Not sure what the cause could be.

Thanks

Roberto