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, 111 insertions, 0 deletions

diff --git a/include/sound/sdca_fdl.h b/include/sound/sdca_fdl.h
new file mode 100644
index 000000000..bc3600cdd
--- /dev/null
+++ b/include/sound/sdca_fdl.h
@@ -0,0 +1,111 @@
+/* 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_FDL_H__
+#define __SDCA_FDL_H__
+
+#include <linux/completion.h>
+#include <linux/workqueue.h>
+
+struct device;
+struct regmap;
+struct sdca_fdl_set;
+struct sdca_function_data;
+struct sdca_interrupt;
+struct sdca_interrupt_info;
+
+/**
+ * struct fdl_state - FDL state structure to keep data between interrupts
+ * @begin: Completion indicating the start of an FDL download cycle.
+ * @done: Completion indicating the end of an FDL download cycle.
+ * @timeout: Delayed work used for timing out UMP transactions.
+ * @lock: Mutex to protect between the timeout work and IRQ handlers.
+ * @interrupt: Pointer to the interrupt struct to which this FDL is attached.
+ * @set: Pointer to the FDL set currently being downloaded.
+ * @file_index: Index of the current file being processed.
+ */
+struct fdl_state {
+	struct completion begin;
+	struct completion done;
+	struct delayed_work timeout;
+	struct mutex lock;
+
+	struct sdca_interrupt *interrupt;
+	struct sdca_fdl_set *set;
+	int file_index;
+};
+
+#define SDCA_CTL_XU_FDLH_COMPLETE	0
+#define SDCA_CTL_XU_FDLH_MORE_FILES	SDCA_CTL_XU_FDLH_SET_IN_PROGRESS
+#define SDCA_CTL_XU_FDLH_FILE_AVAILABLE	(SDCA_CTL_XU_FDLH_TRANSFERRED_FILE | \
+					 SDCA_CTL_XU_FDLH_SET_IN_PROGRESS)
+#define SDCA_CTL_XU_FDLH_MASK		(SDCA_CTL_XU_FDLH_TRANSFERRED_CHUNK | \
+					 SDCA_CTL_XU_FDLH_TRANSFERRED_FILE | \
+					 SDCA_CTL_XU_FDLH_SET_IN_PROGRESS | \
+					 SDCA_CTL_XU_FDLH_RESET_ACK | \
+					 SDCA_CTL_XU_FDLH_REQ_ABORT)
+
+#define SDCA_CTL_XU_FDLD_COMPLETE	0
+#define SDCA_CTL_XU_FDLD_FILE_OK	(SDCA_CTL_XU_FDLH_TRANSFERRED_FILE | \
+					 SDCA_CTL_XU_FDLH_SET_IN_PROGRESS | \
+					 SDCA_CTL_XU_FDLD_ACK_TRANSFER | \
+					 SDCA_CTL_XU_FDLD_NEEDS_SET)
+#define SDCA_CTL_XU_FDLD_MORE_FILES_OK	(SDCA_CTL_XU_FDLH_SET_IN_PROGRESS | \
+					 SDCA_CTL_XU_FDLD_ACK_TRANSFER | \
+					 SDCA_CTL_XU_FDLD_NEEDS_SET)
+#define SDCA_CTL_XU_FDLD_MASK		(SDCA_CTL_XU_FDLD_REQ_RESET | \
+					 SDCA_CTL_XU_FDLD_REQ_ABORT | \
+					 SDCA_CTL_XU_FDLD_ACK_TRANSFER | \
+					 SDCA_CTL_XU_FDLD_NEEDS_SET)
+
+#if IS_ENABLED(CONFIG_SND_SOC_SDCA_FDL)
+
+int sdca_fdl_alloc_state(struct sdca_interrupt *interrupt);
+void sdca_fdl_free_state(struct sdca_interrupt *interrupt);
+
+int sdca_fdl_process(struct sdca_interrupt *interrupt);
+int sdca_fdl_sync(struct device *dev, struct sdca_function_data *function,
+		  struct sdca_interrupt_info *info);
+
+int sdca_reset_function(struct device *dev, struct sdca_function_data *function,
+			struct regmap *regmap);
+
+#else
+
+static inline int sdca_fdl_alloc_state(struct sdca_interrupt *interrupt)
+{
+	return 0;
+}
+
+static inline void sdca_fdl_free_state(struct sdca_interrupt *interrupt)
+{
+}
+
+static inline int sdca_fdl_process(struct sdca_interrupt *interrupt)
+{
+	return 0;
+}
+
+static inline int sdca_fdl_sync(struct device *dev,
+				struct sdca_function_data *function,
+				struct sdca_interrupt_info *info)
+{
+	return 0;
+}
+
+static inline int sdca_reset_function(struct device *dev,
+				      struct sdca_function_data *function,
+				      struct regmap *regmap)
+{
+	return 0;
+}
+
+#endif // CONFIG_SND_SOC_SDCA_FDL
+
+#endif // __SDCA_FDL_H__