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, 66 insertions, 0 deletions

diff --git a/scripts/dtc/libfdt/fdt.h b/scripts/dtc/libfdt/fdt.h
new file mode 100644
index 000000000..a07abfcc7
--- /dev/null
+++ b/scripts/dtc/libfdt/fdt.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) */
+#ifndef FDT_H
+#define FDT_H
+/*
+ * libfdt - Flat Device Tree manipulation
+ * Copyright (C) 2006 David Gibson, IBM Corporation.
+ * Copyright 2012 Kim Phillips, Freescale Semiconductor.
+ */
+
+#ifndef __ASSEMBLER__
+
+struct fdt_header {
+	fdt32_t magic;			 /* magic word FDT_MAGIC */
+	fdt32_t totalsize;		 /* total size of DT block */
+	fdt32_t off_dt_struct;		 /* offset to structure */
+	fdt32_t off_dt_strings;		 /* offset to strings */
+	fdt32_t off_mem_rsvmap;		 /* offset to memory reserve map */
+	fdt32_t version;		 /* format version */
+	fdt32_t last_comp_version;	 /* last compatible version */
+
+	/* version 2 fields below */
+	fdt32_t boot_cpuid_phys;	 /* Which physical CPU id we're
+					    booting on */
+	/* version 3 fields below */
+	fdt32_t size_dt_strings;	 /* size of the strings block */
+
+	/* version 17 fields below */
+	fdt32_t size_dt_struct;		 /* size of the structure block */
+};
+
+struct fdt_reserve_entry {
+	fdt64_t address;
+	fdt64_t size;
+};
+
+struct fdt_node_header {
+	fdt32_t tag;
+	char name[];
+};
+
+struct fdt_property {
+	fdt32_t tag;
+	fdt32_t len;
+	fdt32_t nameoff;
+	char data[];
+};
+
+#endif /* !__ASSEMBLER__ */
+
+#define FDT_MAGIC	0xd00dfeed	/* 4: version, 4: total size */
+#define FDT_TAGSIZE	sizeof(fdt32_t)
+
+#define FDT_BEGIN_NODE	0x1		/* Start node: full name */
+#define FDT_END_NODE	0x2		/* End node */
+#define FDT_PROP	0x3		/* Property: name off,
+					   size, content */
+#define FDT_NOP		0x4		/* nop */
+#define FDT_END		0x9
+
+#define FDT_V1_SIZE	(7*sizeof(fdt32_t))
+#define FDT_V2_SIZE	(FDT_V1_SIZE + sizeof(fdt32_t))
+#define FDT_V3_SIZE	(FDT_V2_SIZE + sizeof(fdt32_t))
+#define FDT_V16_SIZE	FDT_V3_SIZE
+#define FDT_V17_SIZE	(FDT_V16_SIZE + sizeof(fdt32_t))
+
+#endif /* FDT_H */