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, 81 insertions, 0 deletions

diff --git a/scripts/selinux/install_policy.sh b/scripts/selinux/install_policy.sh
new file mode 100755
index 000000000..77368a73f
--- /dev/null
+++ b/scripts/selinux/install_policy.sh
@@ -0,0 +1,81 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+set -e
+if [ `id -u` -ne 0 ]; then
+	echo "$0: must be root to install the selinux policy"
+	exit 1
+fi
+
+SF=`which setfiles` || {
+	echo "Could not find setfiles"
+	echo "Do you have policycoreutils installed?"
+	exit 1
+}
+
+CP=`which checkpolicy` || {
+	echo "Could not find checkpolicy"
+	echo "Do you have checkpolicy installed?"
+	exit 1
+}
+VERS=`$CP -V | awk '{print $1}'`
+
+ENABLED=`which selinuxenabled` || {
+	echo "Could not find selinuxenabled"
+	echo "Do you have libselinux-utils installed?"
+	exit 1
+}
+
+if selinuxenabled; then
+    echo "SELinux is already enabled"
+    echo "This prevents safely relabeling all files."
+    echo "Boot with selinux=0 on the kernel command-line."
+    exit 1
+fi
+
+cd mdp
+./mdp -m policy.conf file_contexts
+$CP -U allow -M -o policy.$VERS policy.conf
+
+mkdir -p /etc/selinux/dummy/policy
+mkdir -p /etc/selinux/dummy/contexts/files
+
+echo "__default__:user_u:s0" > /etc/selinux/dummy/seusers
+echo "base_r:base_t:s0" > /etc/selinux/dummy/contexts/failsafe_context
+echo "base_r:base_t:s0 base_r:base_t:s0" > /etc/selinux/dummy/default_contexts
+cat > /etc/selinux/dummy/contexts/x_contexts <<EOF
+client * user_u:base_r:base_t:s0
+property * user_u:object_r:base_t:s0
+extension * user_u:object_r:base_t:s0
+selection * user_u:object_r:base_t:s0
+event * user_u:object_r:base_t:s0
+EOF
+touch /etc/selinux/dummy/contexts/virtual_domain_context
+touch /etc/selinux/dummy/contexts/virtual_image_context
+
+cp file_contexts /etc/selinux/dummy/contexts/files
+cp dbus_contexts /etc/selinux/dummy/contexts
+cp policy.$VERS /etc/selinux/dummy/policy
+FC_FILE=/etc/selinux/dummy/contexts/files/file_contexts
+
+if [ ! -d /etc/selinux ]; then
+	mkdir -p /etc/selinux
+fi
+if [ -f /etc/selinux/config ]; then
+    echo "/etc/selinux/config exists, moving to /etc/selinux/config.bak."
+    mv /etc/selinux/config /etc/selinux/config.bak
+fi
+echo "Creating new /etc/selinux/config for dummy policy."
+cat > /etc/selinux/config << EOF
+SELINUX=permissive
+SELINUXTYPE=dummy
+EOF
+
+cd /etc/selinux/dummy/contexts/files
+$SF -F file_contexts /
+
+mounts=`cat /proc/$$/mounts | \
+	grep -E "ext[234]|jfs|xfs|jffs2|gfs2|btrfs|f2fs|ocfs2" | \
+	awk '{ print $2 '}`
+$SF -F file_contexts $mounts
+
+echo "-F" > /.autorelabel