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, 35 insertions, 0 deletions

diff --git a/include/trace/misc/fsnotify.h b/include/trace/misc/fsnotify.h
new file mode 100644
index 000000000..a201e1bd6
--- /dev/null
+++ b/include/trace/misc/fsnotify.h
@@ -0,0 +1,35 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Display helpers for fsnotify events
+ */
+
+#include <linux/fsnotify_backend.h>
+
+#define show_fsnotify_mask(mask) \
+	__print_flags(mask, "|", \
+		{ FS_ACCESS,		"ACCESS" }, \
+		{ FS_MODIFY,		"MODIFY" }, \
+		{ FS_ATTRIB,		"ATTRIB" }, \
+		{ FS_CLOSE_WRITE,	"CLOSE_WRITE" }, \
+		{ FS_CLOSE_NOWRITE,	"CLOSE_NOWRITE" }, \
+		{ FS_OPEN,		"OPEN" }, \
+		{ FS_MOVED_FROM,	"MOVED_FROM" }, \
+		{ FS_MOVED_TO,		"MOVED_TO" }, \
+		{ FS_CREATE,		"CREATE" }, \
+		{ FS_DELETE,		"DELETE" }, \
+		{ FS_DELETE_SELF,	"DELETE_SELF" }, \
+		{ FS_MOVE_SELF,		"MOVE_SELF" }, \
+		{ FS_OPEN_EXEC,		"OPEN_EXEC" }, \
+		{ FS_UNMOUNT,		"UNMOUNT" }, \
+		{ FS_Q_OVERFLOW,	"Q_OVERFLOW" }, \
+		{ FS_ERROR,		"ERROR" }, \
+		{ FS_OPEN_PERM,		"OPEN_PERM" }, \
+		{ FS_ACCESS_PERM,	"ACCESS_PERM" }, \
+		{ FS_OPEN_EXEC_PERM,	"OPEN_EXEC_PERM" }, \
+		{ FS_PRE_ACCESS,	"PRE_ACCESS" }, \
+		{ FS_MNT_ATTACH,	"MNT_ATTACH" }, \
+		{ FS_MNT_DETACH,	"MNT_DETACH" }, \
+		{ FS_EVENT_ON_CHILD,	"EVENT_ON_CHILD" }, \
+		{ FS_RENAME,		"RENAME" }, \
+		{ FS_DN_MULTISHOT,	"DN_MULTISHOT" }, \
+		{ FS_ISDIR,		"ISDIR" })