From: sashiko-bot@kernel.org
To: "Jayapal Ashwin Nair" <jayapalashwin.nair@amd.com>,
linux-perf-users@vger.kernel.org
Subject: Re: [PATCH] perf/x86/rapl: Fix use-after-free on rapl_pmus_core on AMD/Hygon
Date: Tue, 13 Oct 2026 09:59:49 +0000 [thread overview]
Message-ID: <sashiko-outbox-169411@kernel.org> (raw)
In-Reply-To: <20261013095051.24777-1-jayapalashwin.nair@amd.com>
> The global rapl_pmus_core pointer can be used after it has been freed in
> two ways:
>
> 1) init_rapl_pmus() stores the newly allocated rapl_pmus in
> *rapl_pmus_ptr before calling init_rapl_pmu(). If init_rapl_pmu()
> fails, rapl_pmus is freed but *rapl_pmus_ptr is not cleared, leaving
> rapl_pmus_core pointing to freed memory. rapl_pmu_init() then jumps
> to core_init_failed, where rapl_advertise() dereferences it.
>
> 2) If perf_pmu_register() fails for the power_core PMU,
> cleanup_rapl_pmus() frees rapl_pmus_core, but the pointer is not
> cleared. rapl_advertise() then dereferences the stale pointer in the
> same way as in 1).
>
> In both cases, rmmod can result in use-after-free and a double free.
>
> Fix this by setting rapl_pmus_core to NULL on both failure paths.
>
> Fixes: b4943b8bfc41 ("perf/x86/rapl: Add core energy counter support for AMD CPUs")
> Signed-off-by: Jayapal Ashwin Nair <jayapalashwin.nair@amd.com>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20261013095051.24777-1-jayapalashwin.nair@amd.com?part=1
prev parent reply other threads:[~2026-10-13 9:59 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-13 9:50 [PATCH] perf/x86/rapl: Fix use-after-free on rapl_pmus_core on AMD/Hygon Jayapal Ashwin Nair
2026-10-13 9:59 ` sashiko-bot [this message]
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