From: sashiko-bot@kernel.org
To: "Dapeng Mi" <dapeng1.mi@linux.intel.com>
Cc: linux-perf-users@vger.kernel.org
Subject: Re: [PATCH 1/2] perf/core: Avoid NULL dereference in mux interval store
Date: Mon, 02 Nov 2026 01:22:09 +0000 [thread overview]
Message-ID: <sashiko-outbox-192803@kernel.org> (raw)
In-Reply-To: <20261102005905.2017784-1-dapeng1.mi@linux.intel.com>
> perf_pmu_register() currently exposes the PMU device and its attributes
> before the per-CPU perf_cpu_pmu_context (cpc) has been allocated and
> initialized. That allows a race where user space writes
> perf_event_mux_interval_ms before cpc is ready, and
> perf_event_mux_interval_ms_store() dereferences it unconditionally.
>
> Fix this by allocating and initializing the per-CPU PMU context before
> making the PMU attribute visible, and add a NULL check in
> perf_event_mux_interval_ms_store() to avoid dereferencing a missing cpc.
>
> Reported-by: Hanxiang Xu <xuhx@hust.edu.cn>
> Closes: https://lore.kernel.org/all/de936c3.1476b.1a162c34cec.Coremail.xuhx@hust.edu.cn/
> Fixes: 62b856397927 ("perf: Add sysfs entry to adjust multiplexing interval per PMU")
> Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Sashiko has reviewed this patch and found no issues.
--
Sashiko AI review · https://sashiko.dev/#/patchset/20261102005905.2017784-1-dapeng1.mi@linux.intel.com?part=1
prev parent reply other threads:[~2026-11-02 1:22 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-11-02 0:59 [PATCH 1/2] perf/core: Avoid NULL dereference in mux interval store Dapeng Mi
2026-11-02 0:59 ` [PATCH 2/2] perf/core: Cancel PMU mux hrtimer before freeing per-CPU context Dapeng Mi
2026-11-02 1:14 ` sashiko-bot
2026-11-02 1:22 ` sashiko-bot [this message]
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