From: "Alexei Starovoitov" <alexei.starovoitov@gmail.com>
To: "Shihuang Liu" <shlomojune6@gmail.com>, <bpf@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>, <stable@vger.kernel.org>,
"Alexei Starovoitov" <ast@kernel.org>,
"Daniel Borkmann" <daniel@iogearbox.net>,
"Andrii Nakryiko" <andrii@kernel.org>,
"Eduard Zingerman" <eddyz87@gmail.com>,
"Kumar Kartikeya Dwivedi" <memxor@gmail.com>,
"Martin KaFai Lau" <martin.lau@linux.dev>,
"Song Liu" <song@kernel.org>,
"Yonghong Song" <yonghong.song@linux.dev>,
"Jiri Olsa" <jolsa@kernel.org>,
"Emil Tsalapatis" <emil@etsalapatis.com>,
"Ihor Solodrai" <ihor.solodrai@linux.dev>,
"Tadeusz Struk" <tadeusz.struk@linaro.org>
Subject: Re: [PATCH] bpf: Fix cgroup link update after a failed effective array rebuild
Date: Thu, 12 Nov 2026 19:57:33 +0000 [thread overview]
Message-ID: <DMTHXFS504S9.2BU4PDLEWG3PX@gmail.com> (raw)
In-Reply-To: <20261112134942.288831-1-shlomojune6@gmail.com>
On Thu Nov 12, 2026 at 1:49 PM UTC, Shihuang Liu wrote:
> replace_effective_prog() uses the position of a cgroup program list
> entry as a physical index into the effective program array. When an
> OOM detach falls back to purge_effective_progs(), the detached entry is
> replaced by a dummy but the other entries keep their position, so the
> list position no longer matches the array index. A later link update
> then writes the new program into the wrong slot, leaving the old
> program pointer in the array. The array does not hold a reference, so
> the old program can be freed while it is still published.
I doubt you managed to reproduce such scenario.
So wont-fix until there is one.
pw-bot: cr
prev parent reply other threads:[~2026-11-12 19:57 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-12 13:49 [PATCH] bpf: Fix cgroup link update after a failed effective array rebuild Shihuang Liu
2026-11-12 14:07 ` sashiko-bot
2026-11-12 19:57 ` Alexei Starovoitov [this message]
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