Unverified Commit fd67a7a1 authored by Trevor Wu's avatar Trevor Wu Committed by Mark Brown
Browse files

ASoC: mediatek: mt8188: fix use-after-free in driver remove path 



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: f6b02647 ("ASoC: mediatek: mt8188: support audio clock control")
Signed-off-by: default avatarTrevor Wu <trevor.wu@mediatek.com>
Reviewed-by: default avatarDouglas Anderson <dianders@chromium.org>
Reviewed-by: default avatarAngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20230601033318.10408-2-trevor.wu@mediatek.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 57d1e890

sound/soc/mediatek/mt8188/mt8188-afe-clk.c

+0 −7
Original line number Diff line number Diff line
@@ -418,13 +418,6 @@ int mt8188_afe_init_clock(struct mtk_base_afe *afe) 
	return 0;

}



void mt8188_afe_deinit_clock(void *priv)

{

	struct mtk_base_afe *afe = priv;



	mt8188_audsys_clk_unregister(afe);

}



int mt8188_afe_enable_clk(struct mtk_base_afe *afe, struct clk *clk)

{

	int ret;

sound/soc/mediatek/mt8188/mt8188-afe-clk.h

+0 −1
Original line number Diff line number Diff line
@@ -100,7 +100,6 @@ int mt8188_afe_get_mclk_source_clk_id(int sel); 
int mt8188_afe_get_mclk_source_rate(struct mtk_base_afe *afe, int apll);

int mt8188_afe_get_default_mclk_source_by_rate(int rate);

int mt8188_afe_init_clock(struct mtk_base_afe *afe);

void mt8188_afe_deinit_clock(void *priv);

int mt8188_afe_enable_clk(struct mtk_base_afe *afe, struct clk *clk);

void mt8188_afe_disable_clk(struct mtk_base_afe *afe, struct clk *clk);

int mt8188_afe_set_clk_rate(struct mtk_base_afe *afe, struct clk *clk,

sound/soc/mediatek/mt8188/mt8188-afe-pcm.c

+0 −4
Original line number Diff line number Diff line
@@ -3185,10 +3185,6 @@ static int mt8188_afe_pcm_dev_probe(struct platform_device *pdev) 
	if (ret)

		return dev_err_probe(dev, ret, "init clock error");



	ret = devm_add_action_or_reset(dev, mt8188_afe_deinit_clock, (void *)afe);

	if (ret)

		return ret;



	spin_lock_init(&afe_priv->afe_ctrl_lock);



	mutex_init(&afe->irq_alloc_lock);

sound/soc/mediatek/mt8188/mt8188-audsys-clk.c

+24 −23
Original line number Diff line number Diff line
@@ -138,6 +138,29 @@ static const struct afe_gate aud_clks[CLK_AUD_NR_CLK] = { 
	GATE_AUD6(CLK_AUD_GASRC11, "aud_gasrc11", "top_asm_h", 11),

};



static void mt8188_audsys_clk_unregister(void *data)

{

	struct mtk_base_afe *afe = data;

	struct mt8188_afe_private *afe_priv = afe->platform_priv;

	struct clk *clk;

	struct clk_lookup *cl;

	int i;



	if (!afe_priv)

		return;



	for (i = 0; i < CLK_AUD_NR_CLK; i++) {

		cl = afe_priv->lookup[i];

		if (!cl)

			continue;



		clk = cl->clk;

		clk_unregister_gate(clk);



		clkdev_drop(cl);

	}

}



int mt8188_audsys_clk_register(struct mtk_base_afe *afe)

{

	struct mt8188_afe_private *afe_priv = afe->platform_priv;
@@ -179,27 +202,5 @@ int mt8188_audsys_clk_register(struct mtk_base_afe *afe) 
		afe_priv->lookup[i] = cl;

	}



	return 0;

}



void mt8188_audsys_clk_unregister(struct mtk_base_afe *afe)

{

	struct mt8188_afe_private *afe_priv = afe->platform_priv;

	struct clk *clk;

	struct clk_lookup *cl;

	int i;



	if (!afe_priv)

		return;



	for (i = 0; i < CLK_AUD_NR_CLK; i++) {

		cl = afe_priv->lookup[i];

		if (!cl)

			continue;



		clk = cl->clk;

		clk_unregister_gate(clk);



		clkdev_drop(cl);

	}

	return devm_add_action_or_reset(afe->dev, mt8188_audsys_clk_unregister, afe);

}

sound/soc/mediatek/mt8188/mt8188-audsys-clk.h

+0 −1
Original line number Diff line number Diff line
@@ -10,6 +10,5 @@ 
#define _MT8188_AUDSYS_CLK_H_



int mt8188_audsys_clk_register(struct mtk_base_afe *afe);

void mt8188_audsys_clk_unregister(struct mtk_base_afe *afe);



#endif