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

On 01/06/2023 05:33, Trevor Wu wrote:

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
2. free afe_priv->clk[i]
3. 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.

Sounds good

Reviewed-by: Alexandre Mergnat amergnat@baylibre.com