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/lib/zlib_inflate/Makefile b/lib/zlib_inflate/Makefile
new file mode 100644
index 000000000..27327d3e9
--- /dev/null
+++ b/lib/zlib_inflate/Makefile
@@ -0,0 +1,20 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# This is a modified version of zlib, which does all memory
+# allocation ahead of time.
+#
+# This is only the decompression, see zlib_deflate for the
+# the compression
+#
+# Decompression needs to be serialized for each memory
+# allocation.
+#
+# (The upsides of the simplification is that you can't get in
+# any nasty situations wrt memory management, and that the
+# uncompression can be done without blocking on allocation).
+#
+
+obj-$(CONFIG_ZLIB_INFLATE) += zlib_inflate.o
+
+zlib_inflate-objs := inffast.o inflate.o infutil.o \
+		     inftrees.o inflate_syms.o