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, 57 insertions, 0 deletions

diff --git a/scripts/kconfig/mconf-cfg.sh b/scripts/kconfig/mconf-cfg.sh
new file mode 100755
index 000000000..1bc304dc2
--- /dev/null
+++ b/scripts/kconfig/mconf-cfg.sh
@@ -0,0 +1,57 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+set -eu
+
+cflags=$1
+libs=$2
+
+PKG="ncursesw"
+PKG2="ncurses"
+
+if [ -n "$(command -v ${HOSTPKG_CONFIG})" ]; then
+	if ${HOSTPKG_CONFIG} --exists $PKG; then
+		${HOSTPKG_CONFIG} --cflags ${PKG} > ${cflags}
+		${HOSTPKG_CONFIG} --libs ${PKG} > ${libs}
+		exit 0
+	fi
+
+	if ${HOSTPKG_CONFIG} --exists ${PKG2}; then
+		${HOSTPKG_CONFIG} --cflags ${PKG2} > ${cflags}
+		${HOSTPKG_CONFIG} --libs ${PKG2} > ${libs}
+		exit 0
+	fi
+fi
+
+# Check the default paths in case pkg-config is not installed.
+# (Even if it is installed, some distributions such as openSUSE cannot
+# find ncurses by pkg-config.)
+if [ -f /usr/include/ncursesw/ncurses.h ]; then
+	echo -D_GNU_SOURCE -I/usr/include/ncursesw > ${cflags}
+	echo -lncursesw > ${libs}
+	exit 0
+fi
+
+if [ -f /usr/include/ncurses/ncurses.h ]; then
+	echo -D_GNU_SOURCE -I/usr/include/ncurses > ${cflags}
+	echo -lncurses > ${libs}
+	exit 0
+fi
+
+# As a final fallback before giving up, check if $HOSTCC knows of a default
+# ncurses installation (e.g. from a vendor-specific sysroot).
+if echo '#include <ncurses.h>' | ${HOSTCC} -E - >/dev/null 2>&1; then
+	echo -D_GNU_SOURCE > ${cflags}
+	echo -lncurses > ${libs}
+	exit 0
+fi
+
+echo >&2 "*"
+echo >&2 "* Unable to find the ncurses package."
+echo >&2 "* Install ncurses (ncurses-devel or libncurses-dev"
+echo >&2 "* depending on your distribution)."
+echo >&2 "*"
+echo >&2 "* You may also need to install ${HOSTPKG_CONFIG} to find the"
+echo >&2 "* ncurses installed in a non-default location."
+echo >&2 "*"
+exit 1