From: Qing Wang <wangqing7171@gmail.com>
To: zeri@umich.edu
Cc: acme@kernel.org, henryzhangjcle@gmail.com,
linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
mingo@redhat.com, peterz@infradead.org,
syzbot+2a077cb788749964cf68@syzkaller.appspotmail.com,
syzkaller-bugs@googlegroups.com, wangqing7171@gmail.com
Subject: Re: [PATCH] perf: Fix data race in perf_event_set_bpf_handler()
Date: Fri, 30 Jan 2026 11:34:20 +0800 [thread overview]
Message-ID: <20260130033420.23612-1-wangqing7171@gmail.com> (raw)
In-Reply-To: <CACkPEmne--T_3bdwJEy8-GEYm4EJF60xSoqbrQ-m_LuZhJhCuQ@mail.gmail.com>
On Wed, 28 Jan 2026 at 05:29, Henry Zhang <zeri@umich.edu> wrote:
> Thanks, this looks good.
I thought my patch is incorrect after review.
1. The RCU protects 'prog->aux' but not 'prog', so 'rcu_dereference(event->prog)'
is incorrect.
2. The UAF issue of 'prog' may not exist. It's needed further anlysis.
Let's forget my patch.
The data race is correctly fixed by your patch but there is still a little
suggestion:
The 'event->prog = NULL' in perf_event_free_bpf_handler is needed WRITE_ONCE.
--
Best regards,
Qing
next prev parent reply other threads:[~2026-01-30 3:34 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-27 2:36 [PATCH] perf: Fix data race in perf_event_set_bpf_handler() Henry Zhang
2026-01-27 8:37 ` Qing Wang
2026-01-30 10:07 ` Peter Zijlstra
2026-02-24 12:29 ` Peter Zijlstra
2026-01-27 10:36 ` Qing Wang
2026-01-27 21:29 ` Henry Zhang
2026-01-28 2:48 ` Qing Wang
2026-01-30 3:34 ` Qing Wang [this message]
2026-01-30 10:23 ` Peter Zijlstra
2026-01-30 13:48 ` Henry Zhang
2026-01-30 20:32 ` Andrii Nakryiko
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