ASoC: mediatek: mt8195: fix use-after-free in driver remove path
authorTrevor Wu <trevor.wu@mediatek.com>
Thu, 1 Jun 2023 03:33:18 +0000 (11:33 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 14 Jun 2023 09:15:31 +0000 (11:15 +0200)
commitc0f9f799bac64381fb2ea322a49073b1a0463bcb
tree6e25273ae50913018a22f669550edb96d8bfe467
parent50f2160afbb8102cb983dd64c0768ae1f64b6647
ASoC: mediatek: mt8195: fix use-after-free in driver remove path

[ Upstream commit dc93f0dcb436dfd24a06c5b3c0f4c5cd9296e8e5 ]

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>
Link: https://lore.kernel.org/r/20230601033318.10408-3-trevor.wu@mediatek.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
sound/soc/mediatek/mt8195/mt8195-afe-clk.c
sound/soc/mediatek/mt8195/mt8195-afe-clk.h
sound/soc/mediatek/mt8195/mt8195-afe-pcm.c
sound/soc/mediatek/mt8195/mt8195-audsys-clk.c
sound/soc/mediatek/mt8195/mt8195-audsys-clk.h