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, 20 insertions, 0 deletions

diff --git a/tools/build/Makefile.include b/tools/build/Makefile.include
new file mode 100644
index 000000000..0e4de8340
--- /dev/null
+++ b/tools/build/Makefile.include
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0-only
+build := -f $(srctree)/tools/build/Makefile.build dir=. obj
+
+# More than just $(Q), we sometimes want to suppress all command output from a
+# recursive make -- even the 'up to date' printout.
+ifeq ($(V),1)
+  Q ?=
+  SILENT_MAKE = +$(Q)$(MAKE)
+else
+  Q ?= @
+  SILENT_MAKE = +$(Q)$(MAKE) --silent
+endif
+
+fixdep:
+	$(SILENT_MAKE) -C $(srctree)/tools/build CFLAGS= LDFLAGS= $(OUTPUT)fixdep
+
+fixdep-clean:
+	$(Q)$(MAKE) -C $(srctree)/tools/build clean
+
+.PHONY: fixdep