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, 54 insertions, 0 deletions

diff --git a/Documentation/driver-api/tee.rst b/Documentation/driver-api/tee.rst
new file mode 100644
index 000000000..4d58ac071
--- /dev/null
+++ b/Documentation/driver-api/tee.rst
@@ -0,0 +1,54 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===============================================
+TEE (Trusted Execution Environment) driver API
+===============================================
+
+Kernel provides a TEE bus infrastructure where a Trusted Application is
+represented as a device identified via Universally Unique Identifier (UUID) and
+client drivers register a table of supported device UUIDs.
+
+TEE bus infrastructure registers following APIs:
+
+match():
+  iterates over the client driver UUID table to find a corresponding
+  match for device UUID. If a match is found, then this particular device is
+  probed via corresponding probe API registered by the client driver. This
+  process happens whenever a device or a client driver is registered with TEE
+  bus.
+
+uevent():
+  notifies user-space (udev) whenever a new device is registered on
+  TEE bus for auto-loading of modularized client drivers.
+
+TEE bus device enumeration is specific to underlying TEE implementation, so it
+is left open for TEE drivers to provide corresponding implementation.
+
+Then TEE client driver can talk to a matched Trusted Application using APIs
+listed in include/linux/tee_drv.h.
+
+TEE client driver example
+-------------------------
+
+Suppose a TEE client driver needs to communicate with a Trusted Application
+having UUID: ``ac6a4085-0e82-4c33-bf98-8eb8e118b6c2``, so driver registration
+snippet would look like::
+
+	static const struct tee_client_device_id client_id_table[] = {
+		{UUID_INIT(0xac6a4085, 0x0e82, 0x4c33,
+			   0xbf, 0x98, 0x8e, 0xb8, 0xe1, 0x18, 0xb6, 0xc2)},
+		{}
+	};
+
+	MODULE_DEVICE_TABLE(tee, client_id_table);
+
+	static struct tee_client_driver client_driver = {
+		.probe		= client_probe,
+		.remove		= client_remove,
+		.id_table	= client_id_table,
+		.driver		= {
+			.name		= DRIVER_NAME,
+		},
+	};
+
+	module_tee_client_driver(client_driver);