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

From: Roberto Sassu <roberto.sassu@huaweicloud.com>
To: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org,
	martin.lau@linux.dev, song@kernel.org, yhs@fb.com,
	john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com,
	haoluo@google.com, jolsa@kernel.org, mykolal@fb.com,
	dhowells@redhat.com, jarkko@kernel.org, rostedt@goodmis.org,
	mingo@redhat.com, paul@paul-moore.com, jmorris@namei.org,
	serge@hallyn.com, shuah@kernel.org, bpf@vger.kernel.org,
	keyrings@vger.kernel.org, linux-security-module@vger.kernel.org,
	linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org,
	deso@posteo.net, Roberto Sassu <roberto.sassu@huawei.com>
Subject: Re: [PATCH v16 00/12] bpf: Add kfuncs for PKCS#7 signature verification
Date: Wed, 07 Sep 2022 16:49:00 +0200	[thread overview]
Message-ID: <57cedc7a3008248b5147d03e2f4bd0b33ad9a146.camel@huaweicloud.com> (raw)
In-Reply-To: <b846cedb14235db6950a55e7eec2eff9e9ab56ec.camel@huaweicloud.com>

On Tue, 2022-09-06 at 09:35 +0200, Roberto Sassu wrote:
> 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@huaweicloud.com> wrote:
> > > From: Roberto Sassu <roberto.sassu@huawei.com>
> > > 
> > > 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@mail.gmail.com.
> > 
> > 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.
> 

Another occurrence, this time with gcc:

https://github.com/robertosassu/vmtest/runs/8230071814?check_suite_focus=true

Roberto