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, 53 insertions, 0 deletions

diff --git a/scripts/checkdeclares.pl b/scripts/checkdeclares.pl
new file mode 100755
index 000000000..f6d551c84
--- /dev/null
+++ b/scripts/checkdeclares.pl
@@ -0,0 +1,53 @@
+#!/usr/bin/env perl
+# SPDX-License-Identifier: GPL-2.0
+#
+# checkdeclares: find struct declared more than once
+#
+# Copyright 2021 Wan Jiabing<wanjiabing@vivo.com>
+# Inspired by checkincludes.pl
+#
+# This script checks for duplicate struct declares.
+# Note that this will not take into consideration macros so
+# you should run this only if you know you do have real dups
+# and do not have them under #ifdef's.
+# You could also just review the results.
+
+use strict;
+
+sub usage {
+	print "Usage: checkdeclares.pl file1.h ...\n";
+	print "Warns of struct declaration duplicates\n";
+	exit 1;
+}
+
+if ($#ARGV < 0) {
+	usage();
+}
+
+my $dup_counter = 0;
+
+foreach my $file (@ARGV) {
+	open(my $f, '<', $file)
+	    or die "Cannot open $file: $!.\n";
+
+	my %declaredstructs = ();
+
+	while (<$f>) {
+		if (m/^\s*struct\s*(\w*);$/o) {
+			++$declaredstructs{$1};
+		}
+	}
+
+	close($f);
+
+	foreach my $structname (keys %declaredstructs) {
+		if ($declaredstructs{$structname} > 1) {
+			print "$file: struct $structname is declared more than once.\n";
+			++$dup_counter;
+		}
+	}
+}
+
+if ($dup_counter == 0) {
+	print "No duplicate struct declares found.\n";
+}