netdev - Re: [PATCH bpf-next v2 3/5] tcp: Use skb__nullable in trace_tcp_send

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240906155742.0bd4d4e3@kernel.org>
Date: Fri, 6 Sep 2024 15:57:42 -0700
From: Jakub Kicinski <kuba@...nel.org>
To: Alexei Starovoitov <alexei.starovoitov@...il.com>
Cc: Philo Lu <lulie@...ux.alibaba.com>, bpf <bpf@...r.kernel.org>, Eric
 Dumazet <edumazet@...gle.com>, Steven Rostedt <rostedt@...dmis.org>, Masami
 Hiramatsu <mhiramat@...nel.org>, Mathieu Desnoyers
 <mathieu.desnoyers@...icios.com>, Martin KaFai Lau <martin.lau@...ux.dev>,
 Alexei Starovoitov <ast@...nel.org>, Daniel Borkmann
 <daniel@...earbox.net>, Andrii Nakryiko <andrii@...nel.org>, Eddy Z
 <eddyz87@...il.com>, Song Liu <song@...nel.org>, Yonghong Song
 <yonghong.song@...ux.dev>, John Fastabend <john.fastabend@...il.com>, KP
 Singh <kpsingh@...nel.org>, Stanislav Fomichev <sdf@...ichev.me>, Hao Luo
 <haoluo@...gle.com>, Jiri Olsa <jolsa@...nel.org>, "David S. Miller"
 <davem@...emloft.net>, Paolo Abeni <pabeni@...hat.com>, Mykola Lysenko
 <mykolal@...com>, Shuah Khan <shuah@...nel.org>, Maxime Coquelin
 <mcoquelin.stm32@...il.com>, Alexandre Torgue
 <alexandre.torgue@...s.st.com>, Kui-Feng Lee <thinker.li@...il.com>,
 Juntong Deng <juntong.deng@...look.com>, jrife@...gle.com, Alan Maguire
 <alan.maguire@...cle.com>, Dave Marchevsky <davemarchevsky@...com>, Daniel
 Xu <dxu@...uu.xyz>, Viktor Malik <vmalik@...hat.com>, Cupertino Miranda
 <cupertino.miranda@...cle.com>, Matt Bobrowski <mattbobrowski@...gle.com>,
 Xuan Zhuo <xuanzhuo@...ux.alibaba.com>, Network Development
 <netdev@...r.kernel.org>, linux-trace-kernel
 <linux-trace-kernel@...r.kernel.org>
Subject: Re: [PATCH bpf-next v2 3/5] tcp: Use skb__nullable in
 trace_tcp_send_reset

On Fri, 6 Sep 2024 15:41:47 -0700 Alexei Starovoitov wrote:
> The urgency is now because the situation is dire.
> The verifier assumes that skb is not null and will remove
> if (!skb) check assuming that it's a dead code.

Meaning verifier currently isn't ready for patch 4?
Or we can crash 6.11-rc6 by attaching to a trace_tcp_send_reset()
and doing
	printf("%d\n", skb->len);
?