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, 70 insertions, 0 deletions

diff --git a/tools/build/tests/run.sh b/tools/build/tests/run.sh
new file mode 100755
index 000000000..2c54e4d43
--- /dev/null
+++ b/tools/build/tests/run.sh
@@ -0,0 +1,70 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+function test_ex {
+	make -C ex V=1 clean > ex.out 2>&1
+	make -C ex V=1 >> ex.out 2>&1
+
+	if [ ! -x ./ex/ex ]; then
+	  echo FAILED
+	  exit -1
+	fi
+
+	make -C ex V=1 clean > /dev/null 2>&1
+	rm -f ex.out
+}
+
+function test_ex_suffix {
+	make -C ex V=1 clean > ex.out 2>&1
+
+	# use -rR to disable make's builtin rules
+	make -rR -C ex V=1 ex.o >> ex.out 2>&1
+	make -rR -C ex V=1 ex.i >> ex.out 2>&1
+	make -rR -C ex V=1 ex.s >> ex.out 2>&1
+
+	if [ -x ./ex/ex ]; then
+	  echo FAILED
+	  exit -1
+	fi
+
+	if [ ! -f ./ex/ex.o -o ! -f ./ex/ex.i -o ! -f ./ex/ex.s ]; then
+	  echo FAILED
+	  exit -1
+	fi
+
+	make -C ex V=1 clean > /dev/null 2>&1
+	rm -f ex.out
+}
+
+function test_ex_include {
+	make -C ex V=1 clean > ex.out 2>&1
+
+	# build with krava.h include
+	touch ex/krava.h
+	make -C ex V=1 CFLAGS=-DINCLUDE >> ex.out 2>&1
+
+	if [ ! -x ./ex/ex ]; then
+	  echo FAILED
+	  exit -1
+	fi
+
+	# build without the include
+	rm -f ex/krava.h ex/ex
+	make -C ex V=1 >> ex.out 2>&1
+
+	if [ ! -x ./ex/ex ]; then
+	  echo FAILED
+	  exit -1
+	fi
+
+	make -C ex V=1 clean > /dev/null 2>&1
+	rm -f ex.out
+}
+
+echo -n Testing..
+
+test_ex
+test_ex_suffix
+test_ex_include
+
+echo OK