From: Leon Hwang <leon.hwang@linux.dev>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>, bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
John Fastabend <john.fastabend@gmail.com>,
Andrii Nakryiko <andrii@kernel.org>,
Eduard Zingerman <eddyz87@gmail.com>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
Martin KaFai Lau <martin.lau@linux.dev>,
Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>,
Jiri Olsa <jolsa@kernel.org>,
Emil Tsalapatis <emil@etsalapatis.com>,
Andrew Morton <akpm@linux-foundation.org>,
Shuah Khan <shuah@kernel.org>,
Puranjay Mohan <puranjay@kernel.org>,
Anton Protopopov <a.s.protopopov@gmail.com>,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org
Subject: Re: [RFC PATCH bpf 0/6] bpf: Disallow interpreter fallback for interpreter-unsupported insns
Date: Wed, 1 Jul 2026 14:20:57 +0800 [thread overview]
Message-ID: <945b57b1-c2ed-44d2-8fa7-07300930783c@linux.dev> (raw)
In-Reply-To: <DJN001X0S57Y.18CKUS4NDDQT1@gmail.com>
On 1/7/26 13:50, Alexei Starovoitov wrote:
> On Tue Jun 30, 2026 at 7:59 PM PDT, Leon Hwang wrote:
>> On 1/7/26 07:12, Alexei Starovoitov wrote:
>>> On Fri Jun 26, 2026 at 8:43 AM PDT, Leon Hwang wrote:
>> [...]
>>>
>>> I don't think we need such fallback in patch [3].
>>
>> Do you mean we can add the internal BPF_ADDR_PERCPU insn support to the
>> interpreter?
>
> No. See why CONFIG_BPF_JIT_ALWAYS_ON was introduced.
> The interpreter is a security hole.
Got it. The commit message of
290af86629b2 ("bpf: introduce BPF_JIT_ALWAYS_ON config") has explained
the security concern.
> It has to be _compiled out_ of the kernel.
> Hence all patches that improve fallback to interpreter are misguided.
> The interpreter has to be removed completely... sooner or later.
Will disallow interpreter fallback for the internal BPF_ADDR_PERCPU
insn.
Thanks,
Leon
prev parent reply other threads:[~2026-07-01 6:21 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-26 15:43 [RFC PATCH bpf 0/6] bpf: Disallow interpreter fallback for interpreter-unsupported insns Leon Hwang
2026-06-26 15:43 ` [RFC PATCH bpf 1/6] bpf: Disallow interpreter fallback for user BPF_ADDR_SPACE_CAST insn Leon Hwang
2026-06-30 14:29 ` KaFai Wan
2026-06-30 14:36 ` Leon Hwang
2026-07-01 1:26 ` Tiezhu Yang
2026-07-01 6:21 ` Leon Hwang
2026-07-01 6:49 ` Tiezhu Yang
2026-07-01 7:02 ` Leon Hwang
2026-07-01 7:29 ` Tiezhu Yang
2026-07-01 8:04 ` Leon Huang Fu
2026-07-01 9:07 ` Tiezhu Yang
2026-07-01 18:47 ` Alexei Starovoitov
2026-06-26 15:43 ` [RFC PATCH bpf 2/6] bpf: Disallow interpreter fallback for arena insn Leon Hwang
2026-06-26 15:43 ` [RFC PATCH bpf 3/6] bpf: Disallow interpreter fallback for BPF_MOV64_PERCPU_REG insn Leon Hwang
2026-06-26 15:43 ` [RFC PATCH bpf 4/6] bpf: Disallow interpreter fallback for internal BPF_PROBE_ATOMIC insn Leon Hwang
2026-06-26 15:43 ` [RFC PATCH bpf 5/6] bpf: Disallow interpreter fallback for gotox insn Leon Hwang
2026-06-26 15:43 ` [RFC PATCH bpf 6/6] lib/test_bpf: Add interpreter-fallback tests Leon Hwang
2026-06-26 16:11 ` [RFC PATCH bpf 0/6] bpf: Disallow interpreter fallback for interpreter-unsupported insns Leon Hwang
2026-06-30 23:12 ` Alexei Starovoitov
2026-07-01 2:59 ` Leon Hwang
2026-07-01 3:05 ` Leon Hwang
2026-07-01 5:50 ` Alexei Starovoitov
2026-07-01 6:20 ` Leon Hwang [this message]
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