[v2,1/2] ASoC: mediatek: mt8188: fix use-after-free in driver remove path
Commit Message
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@mediatek.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
---
sound/soc/mediatek/mt8188/mt8188-afe-clk.c | 7 ---
sound/soc/mediatek/mt8188/mt8188-afe-clk.h | 1 -
sound/soc/mediatek/mt8188/mt8188-afe-pcm.c | 4 --
sound/soc/mediatek/mt8188/mt8188-audsys-clk.c | 47 ++++++++++---------
sound/soc/mediatek/mt8188/mt8188-audsys-clk.h | 1 -
5 files changed, 24 insertions(+), 36 deletions(-)
Comments
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@mediatek.com>
> Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
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
> 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.
Sounds good
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
@@ -436,13 +436,6 @@ 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;
@@ -111,7 +111,6 @@ int mt8188_afe_get_default_mclk_source_by_rate(int rate);
int mt8188_get_apll_by_rate(struct mtk_base_afe *afe, int rate);
int mt8188_get_apll_by_name(struct mtk_base_afe *afe, const char *name);
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,
@@ -3256,10 +3256,6 @@ 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);
@@ -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);
}
@@ -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