From: Eduard Zingerman <eddyz87@gmail.com>
To: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Yonghong Song <yonghong.song@linux.dev>,
bpf <bpf@vger.kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Andrii Nakryiko <andrii@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Kernel Team <kernel-team@fb.com>,
Martin KaFai Lau <martin.lau@kernel.org>,
Daniel Hodges <hodgesd@meta.com>
Subject: Re: [PATCH bpf 1/2] bpf: Fix a kernel verifier crash in stacksafe()
Date: Mon, 12 Aug 2024 10:47:14 -0700 [thread overview]
Message-ID: <d2ca7ec0b51fef86ef8cd71202ee5b6de7dc42cf.camel@gmail.com> (raw)
In-Reply-To: <CAADnVQ+-om1OWRyUvWoiVg5pKM7cxOCVw4wZqdZM1JTRTg4-5g@mail.gmail.com>
On Mon, 2024-08-12 at 10:44 -0700, Alexei Starovoitov wrote:
[...]
> Should we move the check up instead?
>
> if (i >= cur->allocated_stack)
> return false;
>
> Checking it twice looks odd.
A few checks before that, namely:
if (!(old->stack[spi].spilled_ptr.live & REG_LIVE_READ)
&& exact == NOT_EXACT) {
i += BPF_REG_SIZE - 1;
/* explored state didn't use this */
continue;
}
if (old->stack[spi].slot_type[i % BPF_REG_SIZE] == STACK_INVALID)
continue;
if (env->allow_uninit_stack &&
old->stack[spi].slot_type[i % BPF_REG_SIZE] == STACK_MISC)
continue;
Should be done regardless cur->allocated_stack.
next prev parent reply other threads:[~2024-08-12 17:47 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-12 5:21 [PATCH bpf 1/2] bpf: Fix a kernel verifier crash in stacksafe() Yonghong Song
2024-08-12 5:21 ` [PATCH bpf 2/2] selftests/bpf: Add a test to verify previous stacksafe() fix Yonghong Song
2024-08-12 15:07 ` Yonghong Song
2024-08-12 17:38 ` [PATCH bpf 1/2] bpf: Fix a kernel verifier crash in stacksafe() Eduard Zingerman
2024-08-12 17:44 ` Alexei Starovoitov
2024-08-12 17:47 ` Eduard Zingerman [this message]
2024-08-12 17:50 ` Alexei Starovoitov
2024-08-12 17:57 ` Eduard Zingerman
2024-08-12 19:29 ` Alexei Starovoitov
2024-08-12 19:43 ` Eduard Zingerman
2024-08-12 20:02 ` Yonghong Song
2024-08-12 18:26 ` Yonghong Song
2024-08-12 18:30 ` Eduard Zingerman
2024-08-12 18:36 ` Yonghong Song
2024-08-12 18:41 ` Eduard Zingerman
2024-08-12 19:21 ` Yonghong Song
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=d2ca7ec0b51fef86ef8cd71202ee5b6de7dc42cf.camel@gmail.com \
--to=eddyz87@gmail.com \
--cc=alexei.starovoitov@gmail.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=hodgesd@meta.com \
--cc=kernel-team@fb.com \
--cc=martin.lau@kernel.org \
--cc=yonghong.song@linux.dev \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox