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From: Alina Yu <alina_yu@richtek.com>
To: <lgirdwood@gmail.com>, <broonie@kernel.org>, <robh+dt@kernel.org>,
	<krzysztof.kozlowski+dt@linaro.org>, <conor+dt@kernel.org>
CC: <linux-kernel@vger.kernel.org>, <devicetree@vger.kernel.org>,
	<alina_yu@richtek.com>, <johnny_lai@richtek.com>, <cy_huang@richtek.com>
Subject: [PATCH v3 1/6] regulator: rtq2208: Fix invalid memory access when devm_of_regulator_put_matches is called
Date: Fri, 10 May 2024 20:06:20 +0800
Message-ID: <636cbe817ad61a18f291b5ec8938e79043b8a646.1715340537.git.alina_yu@richtek.com>
In-Reply-To: <cover.1715340537.git.alina_yu@richtek.com>
References: <cover.1715340537.git.alina_yu@richtek.com>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain

In this patch, a software bug has been fixed.
rtq2208_ldo_match is no longer a local variable.
It prevents invalid memory access when devm_of_regulator_put_matches
 is called.

Signed-off-by: Alina Yu <alina_yu@richtek.com>
---
v3
- Move Fixes to the start of the series
---
 drivers/regulator/rtq2208-regulator.c | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/drivers/regulator/rtq2208-regulator.c b/drivers/regulator/rtq2208-regulator.c
index 2d54844..dfa293a 100644
--- a/drivers/regulator/rtq2208-regulator.c
+++ b/drivers/regulator/rtq2208-regulator.c
@@ -224,6 +224,11 @@ static const struct regulator_ops rtq2208_regulator_ldo_ops = {
 	.set_suspend_disable = rtq2208_set_suspend_disable,
 };
 
+static struct of_regulator_match rtq2208_ldo_match[] = {
+	{.name = "ldo2", },
+	{.name = "ldo1", },
+};
+
 static unsigned int rtq2208_of_map_mode(unsigned int mode)
 {
 	switch (mode) {
@@ -335,8 +340,7 @@ static const struct linear_range rtq2208_vout_range[] = {
 	REGULATOR_LINEAR_RANGE(1310000, 181, 255, 10000),
 };
 
-static int rtq2208_of_get_fixed_voltage(struct device *dev,
-					struct of_regulator_match *rtq2208_ldo_match, int n_fixed)
+static int rtq2208_of_get_ldo_dvs_ability(struct device *dev)
 {
 	struct device_node *np;
 	struct of_regulator_match *match;
@@ -351,14 +355,14 @@ static int rtq2208_of_get_fixed_voltage(struct device *dev,
 	if (!np)
 		np = dev->of_node;
 
-	ret = of_regulator_match(dev, np, rtq2208_ldo_match, n_fixed);
+	ret = of_regulator_match(dev, np, rtq2208_ldo_match, ARRAY_SIZE(rtq2208_ldo_match));
 
 	of_node_put(np);
 
 	if (ret < 0)
 		return ret;
 
-	for (i = 0; i < n_fixed; i++) {
+	for (i = 0; i < ARRAY_SIZE(rtq2208_ldo_match); i++) {
 		match = rtq2208_ldo_match + i;
 		init_data = match->init_data;
 		rdesc = (struct rtq2208_regulator_desc *)match->driver_data;
@@ -373,8 +377,7 @@ static int rtq2208_of_get_fixed_voltage(struct device *dev,
 	return 0;
 }
 
-static void rtq2208_init_regulator_desc(struct rtq2208_regulator_desc *rdesc, int mtp_sel,
-					int idx, struct of_regulator_match *rtq2208_ldo_match, int *ldo_idx)
+static void rtq2208_init_regulator_desc(struct rtq2208_regulator_desc *rdesc, int mtp_sel, int idx)
 {
 	struct regulator_desc *desc;
 	static const struct {
@@ -432,10 +435,6 @@ static void rtq2208_init_regulator_desc(struct rtq2208_regulator_desc *rdesc, in
 		desc->n_voltages = 1;
 		desc->active_discharge_reg = LDO_RG_SHIFT(curr_info->base, 2);
 
-		rtq2208_ldo_match[*ldo_idx].name = desc->name;
-		rtq2208_ldo_match[*ldo_idx].driver_data = rdesc;
-		rtq2208_ldo_match[(*ldo_idx)++].desc = desc;
-
 		rdesc->suspend_config_reg = curr_info->base;
 		rdesc->suspend_enable_mask = RTQ2208_LDO_EN_STR_MASK;
 	}
@@ -444,8 +443,7 @@ static void rtq2208_init_regulator_desc(struct rtq2208_regulator_desc *rdesc, in
 static int rtq2208_parse_regulator_dt_data(int n_regulator, const unsigned int *regulator_idx_table,
 		struct rtq2208_regulator_desc *rdesc[RTQ2208_LDO_MAX], struct device *dev)
 {
-	struct of_regulator_match rtq2208_ldo_match[2];
-	int mtp_sel, ret, i, idx, ldo_idx = 0;
+	int mtp_sel, i, idx, ret;
 
 	/* get mtp_sel0 or mtp_sel1 */
 	mtp_sel = device_property_read_bool(dev, "richtek,mtp-sel-high");
@@ -457,11 +455,15 @@ static int rtq2208_parse_regulator_dt_data(int n_regulator, const unsigned int *
 		if (!rdesc[i])
 			return -ENOMEM;
 
-		rtq2208_init_regulator_desc(rdesc[i], mtp_sel, idx, rtq2208_ldo_match, &ldo_idx);
+		rtq2208_init_regulator_desc(rdesc[i], mtp_sel, idx);
+
+		/* init ldo dvs ability */
+		if (idx >= RTQ2208_LDO2)
+			rtq2208_ldo_match[idx - RTQ2208_LDO2].desc = &rdesc[i]->desc;
 	}
 
 	/* init ldo fixed_uV */
-	ret = rtq2208_of_get_fixed_voltage(dev, rtq2208_ldo_match, ldo_idx);
+	ret = rtq2208_of_get_ldo_dvs_ability(dev);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to get ldo fixed_uV\n");
 
-- 
2.7.4