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, 45 insertions, 0 deletions

diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h
new file mode 100644
index 000000000..249cea724
--- /dev/null
+++ b/include/scsi/scsi_driver.h
@@ -0,0 +1,45 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SCSI_SCSI_DRIVER_H
+#define _SCSI_SCSI_DRIVER_H
+
+#include <linux/blk_types.h>
+#include <linux/device.h>
+#include <scsi/scsi_cmnd.h>
+
+struct module;
+struct request;
+
+struct scsi_driver {
+	struct device_driver	gendrv;
+
+	int (*probe)(struct scsi_device *);
+	void (*remove)(struct scsi_device *);
+	void (*shutdown)(struct scsi_device *);
+	int (*resume)(struct device *);
+	void (*rescan)(struct device *);
+	blk_status_t (*init_command)(struct scsi_cmnd *);
+	void (*uninit_command)(struct scsi_cmnd *);
+	int (*done)(struct scsi_cmnd *);
+	int (*eh_action)(struct scsi_cmnd *, int);
+	void (*eh_reset)(struct scsi_cmnd *);
+};
+#define to_scsi_driver(drv) \
+	container_of((drv), struct scsi_driver, gendrv)
+
+#define scsi_register_driver(drv) \
+	__scsi_register_driver(drv, THIS_MODULE)
+int __scsi_register_driver(struct scsi_driver *, struct module *);
+#define scsi_unregister_driver(drv) \
+	driver_unregister(&(drv)->gendrv);
+
+extern int scsi_register_interface(struct class_interface *);
+#define scsi_unregister_interface(intf) \
+	class_interface_unregister(intf)
+
+/* make sure not to use it with passthrough commands */
+static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
+{
+	return to_scsi_driver(cmd->device->sdev_gendev.driver);
+}
+
+#endif /* _SCSI_SCSI_DRIVER_H */