| Message ID | 20230601033318.10408-3-trevor.wu@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | ASoC: mediatek: fix use-after-free in driver remove path | expand |
Il 01/06/23 05:33, Trevor Wu ha scritto: > During mt8195_afe_init_clock(), mt8195_audsys_clk_register() was called > followed by several other devm functions. At mt8195_afe_deinit_clock() > located at mt8195_afe_pcm_dev_remove(), mt8195_audsys_clk_unregister() > was called. > > However, there was an issue with the order in which these functions were > called. Specifically, the remove callback of platform_driver was called > before devres released the resource, resulting in a use-after-free issue > during remove time. > > At probe time, the order of calls was: > 1. mt8195_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. mt8195_audsys_clk_unregister > 3. free afe_priv->clk[i] > 2. free afe_priv->clk > > To resolve the problem, we can utilize devm_add_action_or_reset() in > mt8195_audsys_clk_register() so that the remove order can be changed to > 3->2->1. > > Fixes: 6746cc858259 ("ASoC: mediatek: mt8195: add platform driver") > 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 mt8195_afe_init_clock(), mt8195_audsys_clk_register() was called > followed by several other devm functions. At mt8195_afe_deinit_clock() > located at mt8195_afe_pcm_dev_remove(), mt8195_audsys_clk_unregister() > was called. > > However, there was an issue with the order in which these functions were > called. Specifically, the remove callback of platform_driver was called > before devres released the resource, resulting in a use-after-free issue > during remove time. > > At probe time, the order of calls was: > 1. mt8195_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. mt8195_audsys_clk_unregister > 3. free afe_priv->clk[i] > 2. free afe_priv->clk > > To resolve the problem, we can utilize devm_add_action_or_reset() in > mt8195_audsys_clk_register() so that the remove order can be changed to > 3->2->1. Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
diff --git a/sound/soc/mediatek/mt8195/mt8195-afe-clk.c b/sound/soc/mediatek/mt8195/mt8195-afe-clk.c index 9ca2cb8c8a9c..f35318ae0739 100644 --- a/sound/soc/mediatek/mt8195/mt8195-afe-clk.c +++ b/sound/soc/mediatek/mt8195/mt8195-afe-clk.c @@ -410,11 +410,6 @@ int mt8195_afe_init_clock(struct mtk_base_afe *afe) return 0; } -void mt8195_afe_deinit_clock(struct mtk_base_afe *afe) -{ - mt8195_audsys_clk_unregister(afe); -} - int mt8195_afe_enable_clk(struct mtk_base_afe *afe, struct clk *clk) { int ret; diff --git a/sound/soc/mediatek/mt8195/mt8195-afe-clk.h b/sound/soc/mediatek/mt8195/mt8195-afe-clk.h index 40663e31becd..a08c0ee6c860 100644 --- a/sound/soc/mediatek/mt8195/mt8195-afe-clk.h +++ b/sound/soc/mediatek/mt8195/mt8195-afe-clk.h @@ -101,7 +101,6 @@ int mt8195_afe_get_mclk_source_clk_id(int sel); int mt8195_afe_get_mclk_source_rate(struct mtk_base_afe *afe, int apll); int mt8195_afe_get_default_mclk_source_by_rate(int rate); int mt8195_afe_init_clock(struct mtk_base_afe *afe); -void mt8195_afe_deinit_clock(struct mtk_base_afe *afe); int mt8195_afe_enable_clk(struct mtk_base_afe *afe, struct clk *clk); void mt8195_afe_disable_clk(struct mtk_base_afe *afe, struct clk *clk); int mt8195_afe_prepare_clk(struct mtk_base_afe *afe, struct clk *clk); diff --git a/sound/soc/mediatek/mt8195/mt8195-afe-pcm.c b/sound/soc/mediatek/mt8195/mt8195-afe-pcm.c index d22cf1664d8a..a0f2012211fb 100644 --- a/sound/soc/mediatek/mt8195/mt8195-afe-pcm.c +++ b/sound/soc/mediatek/mt8195/mt8195-afe-pcm.c @@ -3224,15 +3224,11 @@ static int mt8195_afe_pcm_dev_probe(struct platform_device *pdev) static void mt8195_afe_pcm_dev_remove(struct platform_device *pdev) { - struct mtk_base_afe *afe = platform_get_drvdata(pdev); - snd_soc_unregister_component(&pdev->dev); pm_runtime_disable(&pdev->dev); if (!pm_runtime_status_suspended(&pdev->dev)) mt8195_afe_runtime_suspend(&pdev->dev); - - mt8195_afe_deinit_clock(afe); } static const struct of_device_id mt8195_afe_pcm_dt_match[] = { diff --git a/sound/soc/mediatek/mt8195/mt8195-audsys-clk.c b/sound/soc/mediatek/mt8195/mt8195-audsys-clk.c index e0670e0dbd5b..38594bc3f2f7 100644 --- a/sound/soc/mediatek/mt8195/mt8195-audsys-clk.c +++ b/sound/soc/mediatek/mt8195/mt8195-audsys-clk.c @@ -148,6 +148,29 @@ static const struct afe_gate aud_clks[CLK_AUD_NR_CLK] = { GATE_AUD6(CLK_AUD_GASRC19, "aud_gasrc19", "top_asm_h", 19), }; +static void mt8195_audsys_clk_unregister(void *data) +{ + struct mtk_base_afe *afe = data; + struct mt8195_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 mt8195_audsys_clk_register(struct mtk_base_afe *afe) { struct mt8195_afe_private *afe_priv = afe->platform_priv; @@ -188,27 +211,5 @@ int mt8195_audsys_clk_register(struct mtk_base_afe *afe) afe_priv->lookup[i] = cl; } - return 0; -} - -void mt8195_audsys_clk_unregister(struct mtk_base_afe *afe) -{ - struct mt8195_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, mt8195_audsys_clk_unregister, afe); } diff --git a/sound/soc/mediatek/mt8195/mt8195-audsys-clk.h b/sound/soc/mediatek/mt8195/mt8195-audsys-clk.h index 239d31016ba7..69db2dd1c9e0 100644 --- a/sound/soc/mediatek/mt8195/mt8195-audsys-clk.h +++ b/sound/soc/mediatek/mt8195/mt8195-audsys-clk.h @@ -10,6 +10,5 @@ #define _MT8195_AUDSYS_CLK_H_ int mt8195_audsys_clk_register(struct mtk_base_afe *afe); -void mt8195_audsys_clk_unregister(struct mtk_base_afe *afe); #endif
During mt8195_afe_init_clock(), mt8195_audsys_clk_register() was called followed by several other devm functions. At mt8195_afe_deinit_clock() located at mt8195_afe_pcm_dev_remove(), mt8195_audsys_clk_unregister() was called. However, there was an issue with the order in which these functions were called. Specifically, the remove callback of platform_driver was called before devres released the resource, resulting in a use-after-free issue during remove time. At probe time, the order of calls was: 1. mt8195_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. mt8195_audsys_clk_unregister 3. free afe_priv->clk[i] 2. free afe_priv->clk To resolve the problem, we can utilize devm_add_action_or_reset() in mt8195_audsys_clk_register() so that the remove order can be changed to 3->2->1. Fixes: 6746cc858259 ("ASoC: mediatek: mt8195: add platform driver") Signed-off-by: Trevor Wu <trevor.wu@mediatek.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> --- sound/soc/mediatek/mt8195/mt8195-afe-clk.c | 5 -- sound/soc/mediatek/mt8195/mt8195-afe-clk.h | 1 - sound/soc/mediatek/mt8195/mt8195-afe-pcm.c | 4 -- sound/soc/mediatek/mt8195/mt8195-audsys-clk.c | 47 ++++++++++--------- sound/soc/mediatek/mt8195/mt8195-audsys-clk.h | 1 - 5 files changed, 24 insertions(+), 34 deletions(-)