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, 220 insertions, 0 deletions

diff --git a/drivers/mfd/max77541.c b/drivers/mfd/max77541.c
new file mode 100644
index 000000000..f91b4f537
--- /dev/null
+++ b/drivers/mfd/max77541.c
@@ -0,0 +1,220 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2022 Analog Devices, Inc.
+ * Driver for the MAX77540 and MAX77541
+ */
+
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max77541.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+static const struct regmap_config max77541_regmap_config = {
+	.reg_bits   = 8,
+	.val_bits   = 8,
+};
+
+static const struct regmap_irq max77541_src_irqs[] = {
+	{ .mask = MAX77541_BIT_INT_SRC_TOPSYS },
+	{ .mask = MAX77541_BIT_INT_SRC_BUCK },
+};
+
+static const struct regmap_irq_chip max77541_src_irq_chip = {
+	.name		= "max77541-src",
+	.status_base	= MAX77541_REG_INT_SRC,
+	.mask_base	= MAX77541_REG_INT_SRC_M,
+	.num_regs	= 1,
+	.irqs		= max77541_src_irqs,
+	.num_irqs       = ARRAY_SIZE(max77541_src_irqs),
+};
+
+static const struct regmap_irq max77541_topsys_irqs[] = {
+	{ .mask = MAX77541_BIT_TOPSYS_INT_TJ_120C },
+	{ .mask = MAX77541_BIT_TOPSYS_INT_TJ_140C },
+	{ .mask = MAX77541_BIT_TOPSYS_INT_TSHDN },
+	{ .mask = MAX77541_BIT_TOPSYS_INT_UVLO },
+	{ .mask = MAX77541_BIT_TOPSYS_INT_ALT_SWO },
+	{ .mask = MAX77541_BIT_TOPSYS_INT_EXT_FREQ_DET },
+};
+
+static const struct regmap_irq_chip max77541_topsys_irq_chip = {
+	.name		= "max77541-topsys",
+	.status_base	= MAX77541_REG_TOPSYS_INT,
+	.mask_base	= MAX77541_REG_TOPSYS_INT_M,
+	.num_regs	= 1,
+	.irqs		= max77541_topsys_irqs,
+	.num_irqs	= ARRAY_SIZE(max77541_topsys_irqs),
+};
+
+static const struct regmap_irq max77541_buck_irqs[] = {
+	{ .mask = MAX77541_BIT_BUCK_INT_M1_POK_FLT },
+	{ .mask = MAX77541_BIT_BUCK_INT_M2_POK_FLT },
+	{ .mask = MAX77541_BIT_BUCK_INT_M1_SCFLT },
+	{ .mask = MAX77541_BIT_BUCK_INT_M2_SCFLT },
+};
+
+static const struct regmap_irq_chip max77541_buck_irq_chip = {
+	.name		= "max77541-buck",
+	.status_base	= MAX77541_REG_BUCK_INT,
+	.mask_base	= MAX77541_REG_BUCK_INT_M,
+	.num_regs	= 1,
+	.irqs		= max77541_buck_irqs,
+	.num_irqs	= ARRAY_SIZE(max77541_buck_irqs),
+};
+
+static const struct regmap_irq max77541_adc_irqs[] = {
+	{ .mask = MAX77541_BIT_ADC_INT_CH1_I },
+	{ .mask = MAX77541_BIT_ADC_INT_CH2_I },
+	{ .mask = MAX77541_BIT_ADC_INT_CH3_I },
+	{ .mask = MAX77541_BIT_ADC_INT_CH6_I },
+};
+
+static const struct regmap_irq_chip max77541_adc_irq_chip = {
+	.name		= "max77541-adc",
+	.status_base	= MAX77541_REG_ADC_INT,
+	.mask_base	= MAX77541_REG_ADC_INT_M,
+	.num_regs	= 1,
+	.irqs		= max77541_adc_irqs,
+	.num_irqs	= ARRAY_SIZE(max77541_adc_irqs),
+};
+
+static const struct mfd_cell max77540_devs[] = {
+	MFD_CELL_OF("max77540-regulator", NULL, NULL, 0, 0, NULL),
+};
+
+static const struct mfd_cell max77541_devs[] = {
+	MFD_CELL_OF("max77541-regulator", NULL, NULL, 0, 0, NULL),
+	MFD_CELL_OF("max77541-adc", NULL, NULL, 0, 0, NULL),
+};
+
+static int max77541_pmic_irq_init(struct device *dev)
+{
+	struct max77541 *max77541 = dev_get_drvdata(dev);
+	int irq = max77541->i2c->irq;
+	int ret;
+
+	ret = devm_regmap_add_irq_chip(dev, max77541->regmap, irq,
+				       IRQF_ONESHOT | IRQF_SHARED, 0,
+				       &max77541_src_irq_chip,
+				       &max77541->irq_data);
+	if (ret)
+		return ret;
+
+	ret = devm_regmap_add_irq_chip(dev, max77541->regmap, irq,
+				       IRQF_ONESHOT | IRQF_SHARED, 0,
+				       &max77541_topsys_irq_chip,
+				       &max77541->irq_topsys);
+	if (ret)
+		return ret;
+
+	ret = devm_regmap_add_irq_chip(dev, max77541->regmap, irq,
+				       IRQF_ONESHOT | IRQF_SHARED, 0,
+				       &max77541_buck_irq_chip,
+				       &max77541->irq_buck);
+	if (ret)
+		return ret;
+
+	if (max77541->id == MAX77541) {
+		ret = devm_regmap_add_irq_chip(dev, max77541->regmap, irq,
+					       IRQF_ONESHOT | IRQF_SHARED, 0,
+					       &max77541_adc_irq_chip,
+					       &max77541->irq_adc);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int max77541_pmic_setup(struct device *dev)
+{
+	struct max77541 *max77541 = dev_get_drvdata(dev);
+	const struct mfd_cell *cells;
+	int n_devs;
+	int ret;
+
+	switch (max77541->id) {
+	case MAX77540:
+		cells =  max77540_devs;
+		n_devs = ARRAY_SIZE(max77540_devs);
+		break;
+	case MAX77541:
+		cells =  max77541_devs;
+		n_devs = ARRAY_SIZE(max77541_devs);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = max77541_pmic_irq_init(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to initialize IRQ\n");
+
+	ret = devm_device_init_wakeup(dev);
+	if (ret)
+		return dev_err_probe(dev, ret, "Unable to init wakeup\n");
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+				    cells, n_devs, NULL, 0, NULL);
+}
+
+static int max77541_probe(struct i2c_client *client)
+{
+	struct device *dev = &client->dev;
+	struct max77541 *max77541;
+
+	max77541 = devm_kzalloc(dev, sizeof(*max77541), GFP_KERNEL);
+	if (!max77541)
+		return -ENOMEM;
+
+	i2c_set_clientdata(client, max77541);
+	max77541->i2c = client;
+
+	max77541->id = (uintptr_t)i2c_get_match_data(client);
+	if (!max77541->id)
+		return -EINVAL;
+
+	max77541->regmap = devm_regmap_init_i2c(client,
+						&max77541_regmap_config);
+	if (IS_ERR(max77541->regmap))
+		return dev_err_probe(dev, PTR_ERR(max77541->regmap),
+				     "Failed to allocate register map\n");
+
+	return max77541_pmic_setup(dev);
+}
+
+static const struct of_device_id max77541_of_id[] = {
+	{
+		.compatible = "adi,max77540",
+		.data = (void *)MAX77540,
+	},
+	{
+		.compatible = "adi,max77541",
+		.data = (void *)MAX77541,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, max77541_of_id);
+
+static const struct i2c_device_id max77541_id[] = {
+	{ "max77540", MAX77540 },
+	{ "max77541", MAX77541 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max77541_id);
+
+static struct i2c_driver max77541_driver = {
+	.driver = {
+		.name = "max77541",
+		.of_match_table = max77541_of_id,
+	},
+	.probe = max77541_probe,
+	.id_table = max77541_id,
+};
+module_i2c_driver(max77541_driver);
+
+MODULE_DESCRIPTION("MAX7740/MAX7741 Driver");
+MODULE_AUTHOR("Okan Sahin <okan.sahin@analog.com>");
+MODULE_LICENSE("GPL");