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, 41 insertions, 0 deletions

diff --git a/fs/unicode/Makefile b/fs/unicode/Makefile
new file mode 100644
index 000000000..d95be7fb9
--- /dev/null
+++ b/fs/unicode/Makefile
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0
+
+ifneq ($(CONFIG_UNICODE),)
+obj-y			+= unicode.o
+endif
+obj-$(CONFIG_UNICODE)	+= utf8data.o
+obj-$(CONFIG_UNICODE_NORMALIZATION_KUNIT_TEST) += tests/utf8_kunit.o
+
+unicode-y := utf8-norm.o utf8-core.o
+
+$(obj)/utf8-data.o: $(obj)/utf8data.c
+
+# In the normal build, the checked-in utf8data.c is just shipped.
+#
+# To generate utf8data.c from UCD, put *.txt files in this directory
+# and pass REGENERATE_UTF8DATA=1 from the command line.
+ifdef REGENERATE_UTF8DATA
+
+quiet_cmd_utf8data = GEN     $@
+      cmd_utf8data = $< \
+		-a $(src)/DerivedAge.txt \
+		-c $(src)/DerivedCombiningClass.txt \
+		-p $(src)/DerivedCoreProperties.txt \
+		-d $(src)/UnicodeData.txt \
+		-f $(src)/CaseFolding.txt \
+		-n $(src)/NormalizationCorrections.txt \
+		-t $(src)/NormalizationTest.txt \
+		-o $@
+
+$(obj)/utf8data.c: $(obj)/mkutf8data $(filter %.txt, $(cmd_utf8data)) FORCE
+	$(call if_changed,utf8data)
+
+else
+
+$(obj)/utf8data.c: $(src)/utf8data.c_shipped FORCE
+	$(call if_changed,copy)
+
+endif
+
+targets += utf8data.c
+hostprogs += mkutf8data