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, 50 insertions, 0 deletions

diff --git a/include/sound/sdca_ump.h b/include/sound/sdca_ump.h
new file mode 100644
index 000000000..f54f9d48c
--- /dev/null
+++ b/include/sound/sdca_ump.h
@@ -0,0 +1,50 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * The MIPI SDCA specification is available for public downloads at
+ * https://www.mipi.org/mipi-sdca-v1-0-download
+ *
+ * Copyright (C) 2025 Cirrus Logic, Inc. and
+ *                    Cirrus Logic International Semiconductor Ltd.
+ */
+
+#ifndef __SDCA_UMP_H__
+#define __SDCA_UMP_H__
+
+struct regmap;
+struct sdca_control;
+struct sdca_entity;
+struct sdca_function_data;
+struct snd_soc_component;
+struct delayed_work;
+
+int sdca_ump_get_owner_host(struct device *dev,
+			    struct regmap *function_regmap,
+			    struct sdca_function_data *function,
+			    struct sdca_entity *entity,
+			    struct sdca_control *control);
+int sdca_ump_set_owner_device(struct device *dev,
+			      struct regmap *function_regmap,
+			      struct sdca_function_data *function,
+			      struct sdca_entity *entity,
+			      struct sdca_control *control);
+int sdca_ump_read_message(struct device *dev,
+			  struct regmap *device_regmap,
+			  struct regmap *function_regmap,
+			  struct sdca_function_data *function,
+			  struct sdca_entity *entity,
+			  unsigned int offset_sel, unsigned int length_sel,
+			  void **msg);
+int sdca_ump_write_message(struct device *dev,
+			   struct regmap *device_regmap,
+			   struct regmap *function_regmap,
+			   struct sdca_function_data *function,
+			   struct sdca_entity *entity,
+			   unsigned int offset_sel, unsigned int msg_offset,
+			   unsigned int length_sel,
+			   void *msg, int msg_len);
+
+void sdca_ump_cancel_timeout(struct delayed_work *work);
+void sdca_ump_schedule_timeout(struct delayed_work *work,
+			       unsigned int timeout_us);
+
+#endif // __SDCA_UMP_H__