From: Daniel Wade <danjwade95@gmail.com>
To: Yiyang Chen <chenyy23@mails.tsinghua.edu.cn>
Cc: Andrii Nakryiko <andrii@kernel.org>,
Alexei Starovoitov <ast@kernel.org>,
bpf@vger.kernel.org, Daniel Borkmann <daniel@iogearbox.net>,
Eduard Zingerman <eddyz87@gmail.com>,
Emil Tsalapatis <emil@etsalapatis.com>,
Ihor Solodrai <ihor.solodrai@linux.dev>,
John Fastabend <john.fastabend@gmail.com>,
Jiri Olsa <jolsa@kernel.org>,
linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org,
Martin KaFai Lau <martin.lau@linux.dev>,
Kumar Kartikeya Dwivedi <memxor@gmail.com>,
Shuah Khan <shuah@kernel.org>, Song Liu <song@kernel.org>,
Yonghong Song <yonghong.song@linux.dev>
Subject: Re: [PATCH bpf-next v3 0/3] bpf: Preserve pointer state for commuted arithmetic
Date: Wed, 22 Jul 2026 21:08:09 +0930 [thread overview]
Message-ID: <20260722210809.382642@kali> (raw)
In-Reply-To: <cover.1784696371.git.chenyy23@mails.tsinghua.edu.cn>
Hi Eduard, Yiyang,
Thanks for the pointer. I independently tested Yiyang's v3 series on the
source-matched f105f3631d51 base with the same kernel config used for my
original report.
Before the series, my impact witness reached chosen-address kernel
read/write and changed UID/GID 65534 with CAP_BPF and CAP_PERFMON to
UID/GID 0 in 3/3 runs. With all three v3 patches applied, the intended
untrusted-pointer positive control still passed, while the impact program
was rejected at "R0 pointer += pointer prohibited" before any address leak
or privilege transition in 3/3 runs.
I also ran the three focused cases added by the v3 series. All passed:
mem_rdonly_untrusted/ldx_is_ok_commuted_addr
dynptr/dynptr_slice_commuted_invalidate
verifier_basic_stack/stack pointer arithmetic preserves frame number
Given that the affected code has shipped and the issue reaches kernel
read/write from a CAP_BPF and CAP_PERFMON context, should this be routed
through bpf and marked for stable rather than bpf-next?
For the v3 series:
Tested-by: Daniel Wade <danjwade95@gmail.com>
Regards,
Daniel
prev parent reply other threads:[~2026-07-22 11:38 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-22 5:27 [PATCH bpf-next v3 0/3] bpf: Preserve pointer state for commuted arithmetic Yiyang Chen
2026-07-22 5:27 ` [PATCH bpf-next v3 1/3] " Yiyang Chen
2026-07-22 5:27 ` [PATCH bpf-next v3 2/3] bpf: Propagate untrusted pointer state in " Yiyang Chen
2026-07-22 5:27 ` [PATCH bpf-next v3 3/3] selftests/bpf: Cover commuted pointer state propagation Yiyang Chen
2026-07-22 5:34 ` sashiko-bot
2026-07-22 11:38 ` Daniel Wade [this message]
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