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, 56 insertions, 0 deletions

diff --git a/tools/bootconfig/scripts/xbc.sh b/tools/bootconfig/scripts/xbc.sh
new file mode 100644
index 000000000..1f0ebf50d
--- /dev/null
+++ b/tools/bootconfig/scripts/xbc.sh
@@ -0,0 +1,56 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only
+
+# bootconfig utility functions
+
+XBC_TMPFILE=
+XBC_BASEDIR=`dirname $0`
+BOOTCONFIG=${BOOTCONFIG:=$XBC_BASEDIR/../bootconfig}
+if [ ! -x "$BOOTCONFIG" ]; then
+	BOOTCONFIG=`which bootconfig`
+	if [ -z "$BOOTCONFIG" ]; then
+		echo "Erorr: bootconfig command is not found" 1>&2
+		exit 1
+	fi
+fi
+
+xbc_cleanup() {
+	if [ "$XBC_TMPFILE" ]; then
+		rm -f "$XBC_TMPFILE"
+	fi
+}
+
+xbc_init() { # bootconfig-file
+	xbc_cleanup
+	XBC_TMPFILE=`mktemp bconf-XXXX`
+	trap xbc_cleanup EXIT TERM
+
+	$BOOTCONFIG -l $1 > $XBC_TMPFILE || exit 1
+}
+
+nr_args() { # args
+	echo $#
+}
+
+xbc_get_val() { # key [maxnum]
+	if [ "$2" ]; then
+		MAXOPT="-L $2"
+	fi
+	grep "^$1 =" $XBC_TMPFILE | cut -d= -f2- | \
+		sed -e 's/", /" /g' -e "s/',/' /g" | \
+		xargs $MAXOPT -n 1 echo
+}
+
+xbc_has_key() { # key
+	grep -q "^$1 =" $XBC_TMPFILE
+}
+
+xbc_has_branch() { # prefix-key
+	grep -q "^$1" $XBC_TMPFILE
+}
+
+xbc_subkeys() { # prefix-key depth [subkey-pattern]
+	__keys=`echo $1 | sed "s/\./ /g"`
+	__s=`nr_args $__keys`
+	grep "^$1$3" $XBC_TMPFILE | cut -d= -f1| cut -d. -f$((__s + 1))-$((__s + $2)) | uniq
+}