From: "Alexei Starovoitov" <alexei.starovoitov@gmail.com>
To: "Ömer Mete Kaya" <omermetekaya0@gmail.com>, daniel@iogearbox.net
Cc: <john.fastabend@gmail.com>, <andrii@kernel.org>,
<eddyz87@gmail.com>, <memxor@gmail.com>, <martin.lau@linux.dev>,
<song@kernel.org>, <yonghong.song@linux.dev>, <jolsa@kernel.org>,
<emil@etsalapatis.com>, <ihor.solodrai@linux.dev>,
<bpf@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH bpf-next v2] bpf: Fix bpf_loop() depth check to use 32-bit max for nr_loops
Date: Mon, 28 Sep 2026 07:48:35 +0000 [thread overview]
Message-ID: <DLQS8S2AXJX4.2UUWRPBC46X2G@gmail.com> (raw)
In-Reply-To: <20260928001609.429840-1-omermetekaya0@gmail.com>
On Mon, Sep 28, 2026 at 03:15 AM Ömer Mete Kaya <omermetekaya0@gmail.com> wrote:
> The verifier compares callback_depth (u32) against reg_umax(), which
> returns the 64-bit upper bound of R1. If the upper 32 bits of R1 are
> set, reg_umax() can be U64_MAX, causing the depth check to be
> ineffective and triggering excessive push_callback_call() invocations
> until the complexity limit is hit.
>
> Use reg_u32_max() instead. The change is sound for both runtime paths:
It's not a fix. Nothing is broken.
pls stop the spam.
pw-bot: cr
prev parent reply other threads:[~2026-09-28 7:48 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-28 0:15 Ömer Mete Kaya
2026-09-28 7:48 ` Alexei Starovoitov [this message]
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