Re: [PATCH v2 1/2] ASoC: mediatek: mt8188: fix use-after-free in driver remove path

[AngeloGioacchino Del Regno]

Il 01/06/23 05:33, Trevor Wu ha scritto:
> During mt8188_afe_init_clock(), mt8188_audsys_clk_register() was called
> followed by several other devm functions. The caller of
> mt8188_afe_init_clock() utilized devm_add_action_or_reset() to call
> mt8188_afe_deinit_clock(). However, the order was incorrect, causing a
> use-after-free issue during remove time.
>
> At probe time, the order of calls was:
> 1. mt8188_audsys_clk_register
> 2. afe_priv->clk = devm_kcalloc
> 3. afe_priv->clk[i] = devm_clk_get
>
> At remove time, the order of calls was:
> 1. mt8188_audsys_clk_unregister
> 3. free afe_priv->clk[i]
> 2. free afe_priv->clk
>
> To resolve the problem, it's necessary to move devm_add_action_or_reset()
> to the appropriate position so that the remove order can be 3->2->1.
>
> Fixes: f6b026479b13 ("ASoC: mediatek: mt8188: support audio clock control")
> Signed-off-by: Trevor Wu <trevor.wu@xxxxxxxxxxxx>
> Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>