From: Qian Cai <cai@lca.pw>
To: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
Yonghong Song <yhs@fb.com>, Andrii Nakryiko <andriin@fb.com>,
John Fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@chromium.org>,
Linux Netdev List <netdev@vger.kernel.org>,
bpf <bpf@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
clang-built-linux <clang-built-linux@googlegroups.com>,
Kees Cook <keescook@chromium.org>
Subject: Re: UBSAN: array-index-out-of-bounds in kernel/bpf/arraymap.c:177
Date: Tue, 19 May 2020 21:55:45 -0400 [thread overview]
Message-ID: <FE7742FF-713E-4310-95E7-9B217662E53E@lca.pw> (raw)
In-Reply-To: <CAEf4BzZKCh7+2TL8GVetxrOKYCoL0U7jTGsO5CbDExs7Px+bYQ@mail.gmail.com>
> On May 19, 2020, at 7:23 PM, Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote:
>
> I agree, it's bad to have this noise. But again, there is nothing
> wrong with the way it's used in BPF code base. We'd gladly use
> flexible array, if we could. But given we can't, I'd say the proper
> solution (in order of my preference) would be:
>
> - don't trigger false error, if zero-sized array is the member of union;
> - or have some sort of annotation at field declaration site (not a
> field access site).
>
> Is that possible?
I am not a compiler expert, but with my experience with all those compiler instrumental technology like KCSAN, KASAN and UBSAN, it seems both options you prop need to modify compilers, i.e., -fsanitize=undefined
prev parent reply other threads:[~2020-05-20 1:55 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-18 2:44 UBSAN: array-index-out-of-bounds in kernel/bpf/arraymap.c:177 Qian Cai
2020-05-18 23:55 ` Andrii Nakryiko
2020-05-19 0:09 ` Qian Cai
2020-05-19 0:25 ` Andrii Nakryiko
2020-05-19 1:00 ` Yonghong Song
2020-05-19 1:30 ` Andrii Nakryiko
2020-05-19 1:36 ` Yonghong Song
2020-05-19 15:00 ` Qian Cai
2020-05-19 19:29 ` Andrii Nakryiko
2020-05-19 20:18 ` Qian Cai
2020-05-19 23:23 ` Andrii Nakryiko
2020-05-20 1:55 ` Qian Cai [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=FE7742FF-713E-4310-95E7-9B217662E53E@lca.pw \
--to=cai@lca.pw \
--cc=andrii.nakryiko@gmail.com \
--cc=andriin@fb.com \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=clang-built-linux@googlegroups.com \
--cc=daniel@iogearbox.net \
--cc=john.fastabend@gmail.com \
--cc=kafai@fb.com \
--cc=keescook@chromium.org \
--cc=kpsingh@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=songliubraving@fb.com \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.