From: Tao Lyu <tao.lyu@epfl.ch>
To: "eddyz87@gmail.com" <eddyz87@gmail.com>,
Shung-Hsi Yu <shung-hsi.yu@suse.com>,
Andrii Nakryiko <andrii@kernel.org>,
"cve@kernel.org" <cve@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: CVE-2023-52920: bpf: support non-r10 register spill/fill to/from stack in precision tracking
Date: Fri, 8 Nov 2024 07:59:22 +0000 [thread overview]
Message-ID: <6ff5182d2cdc4601834bfaa1e3cd1db3@epfl.ch> (raw)
In-Reply-To: <961720ed43b3df26042efc260d433fb6ddf5c44e.camel@gmail.com>
>> Hi Andrii and Eduard,
>
> Hi Shung-Hsi,
>
>> I'm trying to determine the security implication of CVE-2023-52920, or
>> more specifically, what does commit 41f6f64e6999 ("bpf: support non-r10
>> register spill/fill to/from stack in precision tracking") fix.
>> Superficially this looks more like an improvement to the verifier.
>
> It is my understanding as well, that this commit is an optimization to
> avoid some precision marks. I do not see any security implications.
>
> Thanks,
> Eduard
>
> [...]
Hi Andrii, Eduard, and Shung-Hsi,
The previous discussion is here: https://lore.kernel.org/bpf/20231020155842.130257-1-tao.lyu@epfl.ch/
In short, without this patch, the verifier will miss checking an execution path that can have out-of-bound access,
which eventually leads to privilege escalation, like obtaining the root privilege.
Best,
Tao
next prev parent reply other threads:[~2024-11-08 7:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <2024110518-CVE-2023-52920-17f6@gregkh>
2024-11-08 4:42 ` Shung-Hsi Yu
2024-11-08 5:17 ` Eduard Zingerman
2024-11-08 7:59 ` Tao Lyu [this message]
2024-11-12 8:14 ` Shung-Hsi Yu
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