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, 34 insertions, 0 deletions

diff --git a/scripts/stackusage b/scripts/stackusage
new file mode 100755
index 000000000..56ef1ab67
--- /dev/null
+++ b/scripts/stackusage
@@ -0,0 +1,34 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+outfile=""
+now=`date +%s`
+
+while [ $# -gt 0 ]
+do
+    case "$1" in
+        -o)
+	    outfile="$2"
+	    shift 2;;
+	-h)
+	    echo "usage: $0 [-o outfile] <make options/args>"
+	    exit 0;;
+	*)  break;;
+    esac
+done
+
+if [ -z "$outfile" ]
+then
+    outfile=`mktemp --tmpdir stackusage.$$.XXXX`
+fi
+
+KCFLAGS="${KCFLAGS} -fstack-usage" make "$@"
+
+# Prepend directory name to file names, remove column information,
+# make file:line/function/size/type properly tab-separated.
+find . -name '*.su' -newermt "@${now}" -print |                     \
+    xargs perl -MFile::Basename -pe                                 \
+        '$d = dirname($ARGV); s#([^:]+:[0-9]+):[0-9]+:#$d/$1\t#;' | \
+    sort -k3,3nr > "${outfile}"
+
+echo "$0: output written to ${outfile}"