From 2f2020327cc8561d7c520d2f2d9acea84fa7b3a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?N=C3=ADcolas=20F=2E=20R=2E=20A=2E=20Prado?=
<nfraprado@collabora.com>
Date: Tue, 26 Nov 2024 15:09:43 -0500
Subject: [PATCH] ASoC: mediatek: Check num_codecs is not zero to avoid panic
during probe
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Following commit 13f58267cda3 ("ASoC: soc.h: don't create dummy
Component via COMP_DUMMY()"), COMP_DUMMY() became an array with zero
length, and only gets populated with the dummy struct after the card is
registered. Since the sound card driver's probe happens before the card
registration, accessing any of the members of a dummy component during
probe will result in undefined behavior.
This can be observed in the mt8188 and mt8195 machine sound drivers. By
omitting a dai link subnode in the sound card's node in the Devicetree,
the default uninitialized dummy codec is used, and when its dai_name
pointer gets passed to strcmp() it results in a null pointer dereference
and a kernel panic.
In addition to that, set_card_codec_info() in the generic helpers file,
mtk-soundcard-driver.c, will populate a dai link with a dummy codec when
a dai link node is present in DT but with no codec property.
The result is that at probe time, a dummy codec can either be
uninitialized with num_codecs = 0, or be an initialized dummy codec,
with num_codecs = 1 and dai_name = "snd-soc-dummy-dai". In order to
accommodate for both situations, check that num_codecs is not zero
before accessing the codecs' fields but still check for the codec's dai
name against "snd-soc-dummy-dai" as needed.
While at it, also drop the check that dai_name is not null in the mt8192
driver, introduced in commit 4d4e1b6319e5 ("ASoC: mediatek: mt8192:
Check existence of dai_name before dereferencing"), as it is actually
redundant given the preceding num_codecs != 0 check.
Fixes: 13f58267cda3 ("ASoC: soc.h: don't create dummy Component via COMP_DUMMY()")
Signed-off-by: NÃcolas F. R. A. Prado <nfraprado@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Reviewed-by: Fei Shao <fshao@chromium.org>
Acked-by: Trevor Wu <trevor.wu@mediatek.com>
Link: https://patch.msgid.link/20241126-asoc-mtk-dummy-panic-v1-1-42d53e168d2e@collabora.com
Signed-off-by: Mark Brown <broonie@kernel.org>
---
sound/soc/mediatek/mt8188/mt8188-mt6359.c | 9 +++++++--
sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c | 4 ++--
sound/soc/mediatek/mt8195/mt8195-mt6359.c | 9 +++++++--
3 files changed, 16 insertions(+), 6 deletions(-)
diff --git a/sound/soc/mediatek/mt8188/mt8188-mt6359.c b/sound/soc/mediatek/mt8188/mt8188-mt6359.c
index 84abdba9ddb6d..e04b88a57535c 100644
--- a/sound/soc/mediatek/mt8188/mt8188-mt6359.c
+++ b/sound/soc/mediatek/mt8188/mt8188-mt6359.c
@@ -1277,10 +1277,12 @@ static int mt8188_mt6359_soc_card_probe(struct mtk_soc_card_data *soc_card_data,
for_each_card_prelinks(card, i, dai_link) {
if (strcmp(dai_link->name, "DPTX_BE") == 0) {
- if (strcmp(dai_link->codecs->dai_name, "snd-soc-dummy-dai"))
+ if (dai_link->num_codecs &&
+ strcmp(dai_link->codecs->dai_name, "snd-soc-dummy-dai"))
dai_link->init = mt8188_dptx_codec_init;
} else if (strcmp(dai_link->name, "ETDM3_OUT_BE") == 0) {
- if (strcmp(dai_link->codecs->dai_name, "snd-soc-dummy-dai"))
+ if (dai_link->num_codecs &&
+ strcmp(dai_link->codecs->dai_name, "snd-soc-dummy-dai"))
dai_link->init = mt8188_hdmi_codec_init;
} else if (strcmp(dai_link->name, "DL_SRC_BE") == 0 ||
strcmp(dai_link->name, "UL_SRC_BE") == 0) {
@@ -1292,6 +1294,9 @@ static int mt8188_mt6359_soc_card_probe(struct mtk_soc_card_data *soc_card_data,
strcmp(dai_link->name, "ETDM2_OUT_BE") == 0 ||
strcmp(dai_link->name, "ETDM1_IN_BE") == 0 ||
strcmp(dai_link->name, "ETDM2_IN_BE") == 0) {
+ if (!dai_link->num_codecs)
+ continue;
+
if (!strcmp(dai_link->codecs->dai_name, MAX98390_CODEC_DAI)) {
/*
* The TDM protocol settings with fixed 4 slots are defined in
diff --git a/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c b/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c
index 1aba9c75594eb..b1598cc5587e3 100644
--- a/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c
+++ b/sound/soc/mediatek/mt8192/mt8192-mt6359-rt1015-rt5682.c
@@ -1091,7 +1091,7 @@ static int mt8192_mt6359_legacy_probe(struct mtk_soc_card_data *soc_card_data)
dai_link->ignore = 0;
}
- if (dai_link->num_codecs && dai_link->codecs[0].dai_name &&
+ if (dai_link->num_codecs &&
strcmp(dai_link->codecs[0].dai_name, RT1015_CODEC_DAI) == 0)
dai_link->ops = &mt8192_rt1015_i2s_ops;
}
@@ -1119,7 +1119,7 @@ static int mt8192_mt6359_soc_card_probe(struct mtk_soc_card_data *soc_card_data,
int i;
for_each_card_prelinks(card, i, dai_link)
- if (dai_link->num_codecs && dai_link->codecs[0].dai_name &&
+ if (dai_link->num_codecs &&
strcmp(dai_link->codecs[0].dai_name, RT1015_CODEC_DAI) == 0)
dai_link->ops = &mt8192_rt1015_i2s_ops;
}
diff --git a/sound/soc/mediatek/mt8195/mt8195-mt6359.c b/sound/soc/mediatek/mt8195/mt8195-mt6359.c
index 56b9d2433a1eb..2b9cb3248795b 100644
--- a/sound/soc/mediatek/mt8195/mt8195-mt6359.c
+++ b/sound/soc/mediatek/mt8195/mt8195-mt6359.c
@@ -1378,10 +1378,12 @@ static int mt8195_mt6359_soc_card_probe(struct mtk_soc_card_data *soc_card_data,
for_each_card_prelinks(card, i, dai_link) {
if (strcmp(dai_link->name, "DPTX_BE") == 0) {
- if (strcmp(dai_link->codecs->dai_name, "snd-soc-dummy-dai"))
+ if (dai_link->num_codecs &&
+ strcmp(dai_link->codecs->dai_name, "snd-soc-dummy-dai"))
dai_link->init = mt8195_dptx_codec_init;
} else if (strcmp(dai_link->name, "ETDM3_OUT_BE") == 0) {
- if (strcmp(dai_link->codecs->dai_name, "snd-soc-dummy-dai"))
+ if (dai_link->num_codecs &&
+ strcmp(dai_link->codecs->dai_name, "snd-soc-dummy-dai"))
dai_link->init = mt8195_hdmi_codec_init;
} else if (strcmp(dai_link->name, "DL_SRC_BE") == 0 ||
strcmp(dai_link->name, "UL_SRC1_BE") == 0 ||
@@ -1394,6 +1396,9 @@ static int mt8195_mt6359_soc_card_probe(struct mtk_soc_card_data *soc_card_data,
strcmp(dai_link->name, "ETDM2_OUT_BE") == 0 ||
strcmp(dai_link->name, "ETDM1_IN_BE") == 0 ||
strcmp(dai_link->name, "ETDM2_IN_BE") == 0) {
+ if (!dai_link->num_codecs)
+ continue;
+
if (!strcmp(dai_link->codecs->dai_name, MAX98390_CODEC_DAI)) {
if (!(codec_init & MAX98390_CODEC_INIT)) {
dai_link->init = mt8195_max98390_init;
--
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