From: Shung-Hsi Yu <shung-hsi.yu@suse.com>
To: Zhenzhong Wu <jt26wzz@gmail.com>
Cc: stable@vger.kernel.org, Paul Chaignon <paul.chaignon@gmail.com>,
bpf@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, ast@kernel.org,
daniel@iogearbox.net, john.fastabend@gmail.com,
andrii@kernel.org, martin.lau@linux.dev, song@kernel.org,
yonghong.song@linux.dev, kpsingh@kernel.org, haoluo@google.com,
jolsa@kernel.org, menglong8.dong@gmail.com, tamird@kernel.org,
eddyz87@gmail.com
Subject: Re: [RFC PATCH 6.1.y 0/2] bpf: backport scalar not-equal tracking fixes
Date: Tue, 2 Jun 2026 14:42:35 +0800 [thread overview]
Message-ID: <ah56iBM2P_9hF3_L@u94a> (raw)
In-Reply-To: <ah5pf25fhVH9WuU-@u94a>
On Tue, Jun 02, 2026 at 01:47:01PM +0800, Shung-Hsi Yu wrote:
...
> On Tue, Jun 02, 2026 at 02:03:58AM +0800, Zhenzhong Wu wrote:
> > Hi BPF maintainers,
> >
> > This RFC backports two BPF verifier scalar range-tracking fixes to 6.1.y.
> > The series is intended to fix a verifier state-pruning issue where an
> > impossible scalar path can be kept while the real success path is pruned.
> >
> > This is a verifier scalar range-tracking issue, not a helper-specific
> > issue.
> > The visible failure is that the verifier can prune the real success
> > continuation, which should not be skipped, and keep only an impossible one.
> ...
>
> This sounds somewhat similar to the issue fixed in "backport of iterator
> and callback handling fixes" for stable 6.6[1] by @Eduard. Could you try
> to test on the latest stable 6.6.y as well at see if you can reproduce
> the issue there?
...
My mistake, the reproducer you had doesn't use iterator or callback, so
probably not fixed in stable 6.6. I'll take a better look at this later
this week.
> 1: https://lore.kernel.org/stable/20240125001554.25287-1-eddyz87@gmail.com/
> 2: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
next prev parent reply other threads:[~2026-06-02 6:42 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-01 18:03 [RFC PATCH 6.1.y 0/2] bpf: backport scalar not-equal tracking fixes Zhenzhong Wu
2026-06-01 18:03 ` [RFC PATCH 6.1.y 1/2] bpf: drop knowledge-losing __reg_combine_{32,64}_into_{64,32} logic Zhenzhong Wu
2026-06-01 18:04 ` [RFC PATCH 6.1.y 2/2] bpf: make the verifier tracks the "not equal" for regs Zhenzhong Wu
2026-06-02 5:47 ` [RFC PATCH 6.1.y 0/2] bpf: backport scalar not-equal tracking fixes Shung-Hsi Yu
2026-06-02 6:42 ` Shung-Hsi Yu [this message]
2026-06-02 9:17 ` Shung-Hsi Yu
2026-06-02 17:25 ` Zhenzhong Wu
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