From: Eduard Zingerman <eddyz87@gmail.com>
To: Paul Chaignon <paul.chaignon@gmail.com>, bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>
Subject: Re: [PATCH bpf-next 2/2] selftests/bpf: Test invalid narrower ctx load
Date: Mon, 21 Jul 2025 17:11:14 -0700 [thread overview]
Message-ID: <2aa67d27f60af32824e35c4f7c5da956534a4825.camel@gmail.com> (raw)
In-Reply-To: <3d518d4e6c90c3338eea8786291ee3102181ab57.1753099618.git.paul.chaignon@gmail.com>
On Mon, 2025-07-21 at 15:02 +0200, Paul Chaignon wrote:
> This patch adds two selftests to cover invalid narrower loads on the
> context. These used to cause kernel warning before the previous patch.
> To trigger the warning, the load had to be aligned, to read an affected
> pointer field (ex., skb->sk), and not starting at the beginning of the
> pointer field. The new selftests show two such loads of 1B and 4B sizes.
>
> Signed-off-by: Paul Chaignon <paul.chaignon@gmail.com>
> ---
Since we hit a bug here, I think it would be nice to have a test case
for each buggy field if that could be done in a terse way.
Wrapping `invalid_narrow_skb_sk_load` here in a macro and stamping a
few instances seem to be sufficient.
[...]
next prev parent reply other threads:[~2025-07-22 0:11 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-21 12:57 [PATCH bpf-next 1/2] bpf: Reject narrower access to pointer ctx fields Paul Chaignon
2025-07-21 13:02 ` [PATCH bpf-next 2/2] selftests/bpf: Test invalid narrower ctx load Paul Chaignon
2025-07-22 0:11 ` Eduard Zingerman [this message]
2025-07-22 0:08 ` [PATCH bpf-next 1/2] bpf: Reject narrower access to pointer ctx fields Eduard Zingerman
2025-07-22 5:30 ` John Fastabend
2025-07-22 14:44 ` Paul Chaignon
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