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, 99 insertions, 0 deletions

diff --git a/include/scsi/scsi_common.h b/include/scsi/scsi_common.h
new file mode 100644
index 000000000..00c8a16d3
--- /dev/null
+++ b/include/scsi/scsi_common.h
@@ -0,0 +1,99 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Functions used by both the SCSI initiator code and the SCSI target code.
+ */
+
+#ifndef _SCSI_COMMON_H_
+#define _SCSI_COMMON_H_
+
+#include <linux/types.h>
+#include <uapi/linux/pr.h>
+#include <scsi/scsi_proto.h>
+
+/* From the standard INQUIRY data description in SPC-6. */
+#define INQUIRY_VENDOR_OFFSET	8
+#define INQUIRY_VENDOR_LEN	8
+#define INQUIRY_MODEL_OFFSET	16
+#define INQUIRY_MODEL_LEN	16
+#define INQUIRY_REVISION_OFFSET	32
+#define INQUIRY_REVISION_LEN	4
+
+enum scsi_pr_type {
+	SCSI_PR_WRITE_EXCLUSIVE			= 0x01,
+	SCSI_PR_EXCLUSIVE_ACCESS		= 0x03,
+	SCSI_PR_WRITE_EXCLUSIVE_REG_ONLY	= 0x05,
+	SCSI_PR_EXCLUSIVE_ACCESS_REG_ONLY	= 0x06,
+	SCSI_PR_WRITE_EXCLUSIVE_ALL_REGS	= 0x07,
+	SCSI_PR_EXCLUSIVE_ACCESS_ALL_REGS	= 0x08,
+};
+
+enum scsi_pr_type block_pr_type_to_scsi(enum pr_type type);
+enum pr_type scsi_pr_type_to_block(enum scsi_pr_type type);
+
+static inline unsigned
+scsi_varlen_cdb_length(const void *hdr)
+{
+	return ((struct scsi_varlen_cdb_hdr *)hdr)->additional_cdb_length + 8;
+}
+
+extern const unsigned char scsi_command_size_tbl[8];
+#define COMMAND_SIZE(opcode) scsi_command_size_tbl[((opcode) >> 5) & 7]
+
+static inline unsigned
+scsi_command_size(const unsigned char *cmnd)
+{
+	return (cmnd[0] == VARIABLE_LENGTH_CMD) ?
+		scsi_varlen_cdb_length(cmnd) : COMMAND_SIZE(cmnd[0]);
+}
+
+static inline unsigned char
+scsi_command_control(const unsigned char *cmnd)
+{
+	return (cmnd[0] == VARIABLE_LENGTH_CMD) ?
+		cmnd[1] : cmnd[COMMAND_SIZE(cmnd[0]) - 1];
+}
+
+/* Returns a human-readable name for the device */
+extern const char *scsi_device_type(unsigned type);
+
+extern void int_to_scsilun(u64, struct scsi_lun *);
+extern u64 scsilun_to_int(struct scsi_lun *);
+
+/*
+ * This is a slightly modified SCSI sense "descriptor" format header.
+ * The addition is to allow the 0x70 and 0x71 response codes. The idea
+ * is to place the salient data from either "fixed" or "descriptor" sense
+ * format into one structure to ease application processing.
+ *
+ * The original sense buffer should be kept around for those cases
+ * in which more information is required (e.g. the LBA of a MEDIUM ERROR).
+ */
+struct scsi_sense_hdr {		/* See SPC-3 section 4.5 */
+	u8 response_code;	/* permit: 0x0, 0x70, 0x71, 0x72, 0x73 */
+	u8 sense_key;
+	u8 asc;
+	u8 ascq;
+	u8 byte4;
+	u8 byte5;
+	u8 byte6;
+	u8 additional_length;	/* always 0 for fixed sense format */
+};
+
+static inline bool scsi_sense_valid(const struct scsi_sense_hdr *sshdr)
+{
+	if (!sshdr)
+		return false;
+
+	return (sshdr->response_code & 0x70) == 0x70;
+}
+
+extern bool scsi_normalize_sense(const u8 *sense_buffer, int sb_len,
+				 struct scsi_sense_hdr *sshdr);
+
+extern void scsi_build_sense_buffer(int desc, u8 *buf, u8 key, u8 asc, u8 ascq);
+int scsi_set_sense_information(u8 *buf, int buf_len, u64 info);
+int scsi_set_sense_field_pointer(u8 *buf, int buf_len, u16 fp, u8 bp, bool cd);
+extern const u8 * scsi_sense_desc_find(const u8 * sense_buffer, int sb_len,
+				       int desc_type);
+
+#endif /* _SCSI_COMMON_H_ */