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, 132 insertions, 0 deletions

diff --git a/drivers/leds/led-test.c b/drivers/leds/led-test.c
new file mode 100644
index 000000000..ddf9aa967
--- /dev/null
+++ b/drivers/leds/led-test.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2025 Google LLC
+ *
+ * Author: Lee Jones <lee@kernel.org>
+ */
+
+#include <kunit/device.h>
+#include <kunit/test.h>
+#include <linux/device.h>
+#include <linux/leds.h>
+
+#define LED_TEST_POST_REG_BRIGHTNESS 10
+
+struct led_test_ddata {
+	struct led_classdev cdev;
+	struct device *dev;
+};
+
+static enum led_brightness led_test_brightness_get(struct led_classdev *cdev)
+{
+	return LED_TEST_POST_REG_BRIGHTNESS;
+}
+
+static void led_test_class_register(struct kunit *test)
+{
+	struct led_test_ddata *ddata = test->priv;
+	struct led_classdev *cdev_clash, *cdev = &ddata->cdev;
+	struct device *dev = ddata->dev;
+	int ret;
+
+	/* Register a LED class device */
+	cdev->name = "led-test";
+	cdev->brightness_get = led_test_brightness_get;
+	cdev->brightness = 0;
+
+	ret = devm_led_classdev_register(dev, cdev);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_EQ(test, cdev->max_brightness, LED_FULL);
+	KUNIT_EXPECT_EQ(test, cdev->brightness, LED_TEST_POST_REG_BRIGHTNESS);
+	KUNIT_EXPECT_STREQ(test, cdev->dev->kobj.name, "led-test");
+
+	/* Register again with the same name - expect it to pass with the LED renamed */
+	cdev_clash = devm_kmemdup(dev, cdev, sizeof(*cdev), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cdev_clash);
+
+	ret = devm_led_classdev_register(dev, cdev_clash);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	KUNIT_EXPECT_STREQ(test, cdev_clash->dev->kobj.name, "led-test_1");
+	KUNIT_EXPECT_STREQ(test, cdev_clash->name, "led-test");
+
+	/* Enable name conflict rejection and register with the same name again - expect failure */
+	cdev_clash->flags |= LED_REJECT_NAME_CONFLICT;
+	ret = devm_led_classdev_register(dev, cdev_clash);
+	KUNIT_EXPECT_EQ(test, ret, -EEXIST);
+}
+
+static void led_test_class_add_lookup_and_get(struct kunit *test)
+{
+	struct led_test_ddata *ddata = test->priv;
+	struct led_classdev *cdev = &ddata->cdev, *cdev_get;
+	struct device *dev = ddata->dev;
+	struct led_lookup_data lookup;
+	int ret;
+
+	/* First, register a LED class device */
+	cdev->name = "led-test";
+	ret = devm_led_classdev_register(dev, cdev);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	/* Then make the LED available for lookup */
+	lookup.provider = cdev->name;
+	lookup.dev_id = dev_name(dev);
+	lookup.con_id = "led-test-1";
+	led_add_lookup(&lookup);
+
+	/* Finally, attempt to look it up via the API - imagine this was an orthogonal driver */
+	cdev_get = devm_led_get(dev, "led-test-1");
+	KUNIT_ASSERT_FALSE(test, IS_ERR(cdev_get));
+
+	KUNIT_EXPECT_STREQ(test, cdev_get->name, cdev->name);
+
+	led_remove_lookup(&lookup);
+}
+
+static struct kunit_case led_test_cases[] = {
+	KUNIT_CASE(led_test_class_register),
+	KUNIT_CASE(led_test_class_add_lookup_and_get),
+	{ }
+};
+
+static int led_test_init(struct kunit *test)
+{
+	struct led_test_ddata *ddata;
+	struct device *dev;
+
+	ddata = kunit_kzalloc(test, sizeof(*ddata), GFP_KERNEL);
+	if (!ddata)
+		return -ENOMEM;
+
+	test->priv = ddata;
+
+	dev = kunit_device_register(test, "led_test");
+	if (IS_ERR(dev))
+		return PTR_ERR(dev);
+
+	ddata->dev = get_device(dev);
+
+	return 0;
+}
+
+static void led_test_exit(struct kunit *test)
+{
+	struct led_test_ddata *ddata = test->priv;
+
+	if (ddata && ddata->dev)
+		put_device(ddata->dev);
+}
+
+static struct kunit_suite led_test_suite = {
+	.name = "led",
+	.init = led_test_init,
+	.exit = led_test_exit,
+	.test_cases = led_test_cases,
+};
+kunit_test_suite(led_test_suite);
+
+MODULE_AUTHOR("Lee Jones <lee@kernel.org>");
+MODULE_DESCRIPTION("KUnit tests for the LED framework");
+MODULE_LICENSE("GPL");