staging: rtl8723bs: fix OOB read in rtw_action_frame_parse()grafted

rtw_action_frame_parse() takes a frame_len parameter but never
actually checks it before indexing into the frame body:

	const u8 *frame_body = frame + sizeof(struct ieee80211_hdr_3addr);
	...
	c = frame_body[0];
	...
	a = frame_body[1];

frame_body already points 24 bytes (sizeof(struct
ieee80211_hdr_3addr)) into frame, so reading frame_body[0] and
frame_body[1] requires frame_len >= 26. A management action frame
shorter than that (e.g. exactly 24 bytes, the minimum a malicious
peer can send) causes a 1-2 byte out-of-bounds read.

This is reachable from rtw_cfg80211_monitor_if_xmit_entry() and
cfg80211_rtw_mgmt_tx() in ioctl_cfg80211.c, both of which pass
attacker/user-influenced frame buffers and lengths straight through.

Add the missing length check before frame_body is dereferenced.

Fixes: 554c0a3abf216 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable@vger.kernel.org
Signed-off-by: Muhammad Bilal <meatuni001@gmail.com>
Link: https://patch.msgid.link/20260728125456.32359-3-meatuni001@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 450 insertions, 0 deletions

diff --git a/drivers/base/regmap/regmap-i2c.c b/drivers/base/regmap/regmap-i2c.c
new file mode 100644
index 000000000..51a04961f
--- /dev/null
+++ b/drivers/base/regmap/regmap-i2c.c
@@ -0,0 +1,450 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Register map access API - I2C support
+//
+// Copyright 2011 Wolfson Microelectronics plc
+//
+// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+
+#include <linux/regmap.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+
+#include "internal.h"
+
+static int regmap_smbus_byte_reg_read(void *context, unsigned int reg,
+				      unsigned int *val)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	int ret;
+
+	if (reg > 0xff)
+		return -EINVAL;
+
+	ret = i2c_smbus_read_byte_data(i2c, reg);
+	if (ret < 0)
+		return ret;
+
+	*val = ret;
+
+	return 0;
+}
+
+static int regmap_smbus_byte_reg_write(void *context, unsigned int reg,
+				       unsigned int val)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+
+	if (val > 0xff || reg > 0xff)
+		return -EINVAL;
+
+	return i2c_smbus_write_byte_data(i2c, reg, val);
+}
+
+static const struct regmap_bus regmap_smbus_byte = {
+	.reg_write = regmap_smbus_byte_reg_write,
+	.reg_read = regmap_smbus_byte_reg_read,
+};
+
+static int regmap_smbus_word_reg_read(void *context, unsigned int reg,
+				      unsigned int *val)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	int ret;
+
+	if (reg > 0xff)
+		return -EINVAL;
+
+	ret = i2c_smbus_read_word_data(i2c, reg);
+	if (ret < 0)
+		return ret;
+
+	*val = ret;
+
+	return 0;
+}
+
+static int regmap_smbus_word_reg_write(void *context, unsigned int reg,
+				       unsigned int val)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+
+	if (val > 0xffff || reg > 0xff)
+		return -EINVAL;
+
+	return i2c_smbus_write_word_data(i2c, reg, val);
+}
+
+static const struct regmap_bus regmap_smbus_word = {
+	.reg_write = regmap_smbus_word_reg_write,
+	.reg_read = regmap_smbus_word_reg_read,
+};
+
+static int regmap_smbus_word_read_swapped(void *context, unsigned int reg,
+					  unsigned int *val)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	int ret;
+
+	if (reg > 0xff)
+		return -EINVAL;
+
+	ret = i2c_smbus_read_word_swapped(i2c, reg);
+	if (ret < 0)
+		return ret;
+
+	*val = ret;
+
+	return 0;
+}
+
+static int regmap_smbus_word_write_swapped(void *context, unsigned int reg,
+					   unsigned int val)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+
+	if (val > 0xffff || reg > 0xff)
+		return -EINVAL;
+
+	return i2c_smbus_write_word_swapped(i2c, reg, val);
+}
+
+static const struct regmap_bus regmap_smbus_word_swapped = {
+	.reg_write = regmap_smbus_word_write_swapped,
+	.reg_read = regmap_smbus_word_read_swapped,
+};
+
+static int regmap_i2c_write(void *context, const void *data, size_t count)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	int ret;
+
+	ret = i2c_master_send(i2c, data, count);
+	if (ret == count)
+		return 0;
+	else if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int regmap_i2c_gather_write(void *context,
+				   const void *reg, size_t reg_size,
+				   const void *val, size_t val_size)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct i2c_msg xfer[2];
+	int ret;
+
+	/* If the I2C controller can't do a gather tell the core, it
+	 * will substitute in a linear write for us.
+	 */
+	if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_NOSTART))
+		return -ENOTSUPP;
+
+	xfer[0].addr = i2c->addr;
+	xfer[0].flags = 0;
+	xfer[0].len = reg_size;
+	xfer[0].buf = (void *)reg;
+
+	xfer[1].addr = i2c->addr;
+	xfer[1].flags = I2C_M_NOSTART;
+	xfer[1].len = val_size;
+	xfer[1].buf = (void *)val;
+
+	ret = i2c_transfer(i2c->adapter, xfer, 2);
+	if (ret == 2)
+		return 0;
+	if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static int regmap_i2c_read(void *context,
+			   const void *reg, size_t reg_size,
+			   void *val, size_t val_size)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct i2c_msg xfer[2];
+	int ret;
+
+	xfer[0].addr = i2c->addr;
+	xfer[0].flags = 0;
+	xfer[0].len = reg_size;
+	xfer[0].buf = (void *)reg;
+
+	xfer[1].addr = i2c->addr;
+	xfer[1].flags = I2C_M_RD;
+	xfer[1].len = val_size;
+	xfer[1].buf = val;
+
+	ret = i2c_transfer(i2c->adapter, xfer, 2);
+	if (ret == 2)
+		return 0;
+	else if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static const struct regmap_bus regmap_i2c = {
+	.write = regmap_i2c_write,
+	.gather_write = regmap_i2c_gather_write,
+	.read = regmap_i2c_read,
+	.reg_format_endian_default = REGMAP_ENDIAN_BIG,
+	.val_format_endian_default = REGMAP_ENDIAN_BIG,
+};
+
+static int regmap_i2c_smbus_i2c_write(void *context, const void *data,
+				      size_t count)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+
+	if (count < 1)
+		return -EINVAL;
+
+	--count;
+	return i2c_smbus_write_i2c_block_data(i2c, ((u8 *)data)[0], count,
+					      ((u8 *)data + 1));
+}
+
+static int regmap_i2c_smbus_i2c_read(void *context, const void *reg,
+				     size_t reg_size, void *val,
+				     size_t val_size)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	int ret;
+
+	if (reg_size != 1 || val_size < 1)
+		return -EINVAL;
+
+	ret = i2c_smbus_read_i2c_block_data(i2c, ((u8 *)reg)[0], val_size, val);
+	if (ret == val_size)
+		return 0;
+	else if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static const struct regmap_bus regmap_i2c_smbus_i2c_block = {
+	.write = regmap_i2c_smbus_i2c_write,
+	.read = regmap_i2c_smbus_i2c_read,
+	.max_raw_read = I2C_SMBUS_BLOCK_MAX - 1,
+	.max_raw_write = I2C_SMBUS_BLOCK_MAX - 1,
+};
+
+static int regmap_i2c_smbus_i2c_write_reg16(void *context, const void *data,
+				      size_t count)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+
+	if (count < 2)
+		return -EINVAL;
+
+	count--;
+	return i2c_smbus_write_i2c_block_data(i2c, ((u8 *)data)[0], count,
+					      (u8 *)data + 1);
+}
+
+static int regmap_i2c_smbus_i2c_read_reg16(void *context, const void *reg,
+				     size_t reg_size, void *val,
+				     size_t val_size)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	int ret, count, len = val_size;
+
+	if (reg_size != 2)
+		return -EINVAL;
+
+	ret = i2c_smbus_write_byte_data(i2c, ((u16 *)reg)[0] & 0xff,
+					((u16 *)reg)[0] >> 8);
+	if (ret < 0)
+		return ret;
+
+	count = 0;
+	do {
+		/* Current Address Read */
+		ret = i2c_smbus_read_byte(i2c);
+		if (ret < 0)
+			break;
+
+		*((u8 *)val++) = ret;
+		count++;
+		len--;
+	} while (len > 0);
+
+	if (count == val_size)
+		return 0;
+	else if (ret < 0)
+		return ret;
+	else
+		return -EIO;
+}
+
+static const struct regmap_bus regmap_i2c_smbus_i2c_block_reg16 = {
+	.write = regmap_i2c_smbus_i2c_write_reg16,
+	.read = regmap_i2c_smbus_i2c_read_reg16,
+	.max_raw_read = I2C_SMBUS_BLOCK_MAX - 2,
+	.max_raw_write = I2C_SMBUS_BLOCK_MAX - 2,
+};
+
+/*
+ * SMBus byte/word reg16 support for adapters that have SMBUS_BYTE_DATA
+ * and SMBUS_WORD_DATA but lack I2C_FUNC_I2C and I2C_FUNC_SMBUS_I2C_BLOCK,
+ * such as the AMD PIIX4.
+ *
+ * READ:  set 16-bit EEPROM address via write_byte_data(addr_lo, addr_hi),
+ *        then sequentially read bytes via read_byte() (EEPROM auto-
+ *        increments the address pointer).  Same as the I2C-block reg16
+ *        read path above.
+ *
+ * WRITE: encode the low address byte and data into a word transaction:
+ *        write_word_data(addr_hi, (data_byte << 8) | addr_lo).
+ *        Only single-byte writes are supported (one value per transaction).
+ */
+static int regmap_smbus_word_write_reg16(void *context, const void *data,
+					 size_t count)
+{
+	struct device *dev = context;
+	struct i2c_client *i2c = to_i2c_client(dev);
+	u8 addr_hi, addr_lo, val;
+
+	/*
+	 * data layout: [addr_hi, addr_lo, val0, val1, ...].
+	 * Only single-byte value writes are supported; multi-byte would
+	 * require raw I2C (or repeated word writes with incrementing address).
+	 */
+	if (count != 3)
+		return -EINVAL;
+
+	addr_hi = ((u8 *)data)[0];
+	addr_lo = ((u8 *)data)[1];
+	val = ((u8 *)data)[2];
+
+	return i2c_smbus_write_word_data(i2c, addr_hi,
+					 ((u16)val << 8) | addr_lo);
+}
+
+static const struct regmap_bus regmap_smbus_byte_word_reg16 = {
+	.write = regmap_smbus_word_write_reg16,
+	.read = regmap_i2c_smbus_i2c_read_reg16,
+	.max_raw_read = I2C_SMBUS_BLOCK_MAX - 2,
+	.max_raw_write = 1,
+};
+
+static const struct regmap_bus *regmap_get_i2c_bus(struct i2c_client *i2c,
+					const struct regmap_config *config)
+{
+	const struct i2c_adapter_quirks *quirks;
+	const struct regmap_bus *bus = NULL;
+	struct regmap_bus *ret_bus;
+	u16 max_read = 0, max_write = 0;
+
+	if (i2c_check_functionality(i2c->adapter, I2C_FUNC_I2C))
+		bus = &regmap_i2c;
+	else if (config->val_bits == 8 && config->reg_bits == 8 &&
+		 i2c_check_functionality(i2c->adapter,
+					 I2C_FUNC_SMBUS_I2C_BLOCK))
+		bus = &regmap_i2c_smbus_i2c_block;
+	else if (config->val_bits == 8 && config->reg_bits == 16 &&
+		i2c_check_functionality(i2c->adapter,
+					I2C_FUNC_SMBUS_I2C_BLOCK))
+		bus = &regmap_i2c_smbus_i2c_block_reg16;
+	else if (config->val_bits == 8 && config->reg_bits == 16 &&
+		 i2c_check_functionality(i2c->adapter,
+					I2C_FUNC_SMBUS_BYTE_DATA |
+					I2C_FUNC_SMBUS_WORD_DATA))
+		bus = &regmap_smbus_byte_word_reg16;
+	else if (config->val_bits == 16 && config->reg_bits == 8 &&
+		 i2c_check_functionality(i2c->adapter,
+					 I2C_FUNC_SMBUS_WORD_DATA))
+		switch (regmap_get_val_endian(&i2c->dev, NULL, config)) {
+		case REGMAP_ENDIAN_LITTLE:
+			bus = &regmap_smbus_word;
+			break;
+		case REGMAP_ENDIAN_BIG:
+			bus = &regmap_smbus_word_swapped;
+			break;
+		default:		/* everything else is not supported */
+			break;
+		}
+	else if (config->val_bits == 8 && config->reg_bits == 8 &&
+		 i2c_check_functionality(i2c->adapter,
+					 I2C_FUNC_SMBUS_BYTE_DATA))
+		bus = &regmap_smbus_byte;
+
+	if (!bus)
+		return ERR_PTR(-ENOTSUPP);
+
+	quirks = i2c->adapter->quirks;
+	if (quirks) {
+		if (quirks->max_read_len &&
+		    (bus->max_raw_read == 0 || bus->max_raw_read > quirks->max_read_len))
+			max_read = quirks->max_read_len;
+
+		if (quirks->max_write_len &&
+		    (bus->max_raw_write == 0 || bus->max_raw_write > quirks->max_write_len))
+			max_write = quirks->max_write_len -
+				(config->reg_bits + config->pad_bits) / BITS_PER_BYTE;
+
+		if (max_read || max_write) {
+			ret_bus = kmemdup(bus, sizeof(*bus), GFP_KERNEL);
+			if (!ret_bus)
+				return ERR_PTR(-ENOMEM);
+			ret_bus->free_on_exit = true;
+			ret_bus->max_raw_read = max_read;
+			ret_bus->max_raw_write = max_write;
+			bus = ret_bus;
+		}
+	}
+
+	return bus;
+}
+
+struct regmap *__regmap_init_i2c(struct i2c_client *i2c,
+				 const struct regmap_config *config,
+				 struct lock_class_key *lock_key,
+				 const char *lock_name)
+{
+	const struct regmap_bus *bus = regmap_get_i2c_bus(i2c, config);
+
+	if (IS_ERR(bus))
+		return ERR_CAST(bus);
+
+	return __regmap_init(&i2c->dev, bus, &i2c->dev, config,
+			     lock_key, lock_name);
+}
+EXPORT_SYMBOL_GPL(__regmap_init_i2c);
+
+struct regmap *__devm_regmap_init_i2c(struct i2c_client *i2c,
+				      const struct regmap_config *config,
+				      struct lock_class_key *lock_key,
+				      const char *lock_name)
+{
+	const struct regmap_bus *bus = regmap_get_i2c_bus(i2c, config);
+
+	if (IS_ERR(bus))
+		return ERR_CAST(bus);
+
+	return __devm_regmap_init(&i2c->dev, bus, &i2c->dev, config,
+				  lock_key, lock_name);
+}
+EXPORT_SYMBOL_GPL(__devm_regmap_init_i2c);
+
+MODULE_DESCRIPTION("Register map access API - I2C support");
+MODULE_LICENSE("GPL");