From: "Alexei Starovoitov" <alexei.starovoitov@gmail.com>
To: "Chris Down" <chris@chrisdown.name>
Cc: "Nuoqi Gui" <gnq25@mails.tsinghua.edu.cn>,
"Alexei Starovoitov" <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Andrii Nakryiko" <andrii@kernel.org>,
"Eduard Zingerman" <eddyz87@gmail.com>,
"Kumar Kartikeya Dwivedi" <memxor@gmail.com>,
"Martin KaFai Lau" <martin.lau@linux.dev>,
"Mykyta Yatsenko" <yatsenko@meta.com>,
"Shuah Khan" <shuah@kernel.org>, <bpf@vger.kernel.org>,
<linux-kselftest@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH bpf 0/2] bpf: Gate dynptr probe-read kfuncs like helpers
Date: Sat, 31 Oct 2026 20:58:02 +0000 [thread overview]
Message-ID: <DMJBP7BG3GE8.1ZXVVR0YIM9OO@gmail.com> (raw)
In-Reply-To: <auN_R9gCBqNwEkKV@chrisdown.name>
On Thu Oct 29, 2026 at 5:15 PM UTC, Chris Down wrote:
> Hey Alexei,
>
> Alexei Starovoitov writes:
>> It's fine as-is. Won't fix.
>
> Could you expand a bit on the lockdown side of this? I ran into the same
> discrepancy independently and was preparing fixes until I found this thread
> while looking for prior discussion.
>
> The CAP_PERFMON side is now covered by 81c975aae375 ("bpf: Require CAP_PERFMON
> for kfuncs reading memory"), but the probe_read_kernel helpers still check
> LOCKDOWN_BPF_READ_KERNEL while the matching dynptr kfuncs don't. Is that
> intentional?
lockdown is a security circus. It was broken from day one. It never worked.
So all these 'ohh let's fix it' missing the point.
prev parent reply other threads:[~2026-10-31 20:58 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-15 8:31 [PATCH bpf 0/2] bpf: Gate dynptr probe-read kfuncs like helpers Nuoqi Gui
2026-06-15 8:31 ` [PATCH bpf 1/2] " Nuoqi Gui
2026-06-15 8:55 ` sashiko-bot
2026-06-15 8:31 ` [PATCH bpf 2/2] selftests/bpf: Cover dynptr probe-read kfunc capability gate Nuoqi Gui
2026-06-15 8:41 ` sashiko-bot
2026-06-15 9:36 ` Nuoqi Gui
2026-06-15 15:48 ` [PATCH bpf 0/2] bpf: Gate dynptr probe-read kfuncs like helpers Alexei Starovoitov
2026-10-29 17:15 ` Chris Down
2026-10-31 20:58 ` Alexei Starovoitov [this message]
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