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, 51 insertions, 0 deletions

diff --git a/include/trace/events/fsnotify.h b/include/trace/events/fsnotify.h
new file mode 100644
index 000000000..341bbd57a
--- /dev/null
+++ b/include/trace/events/fsnotify.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fsnotify
+
+#if !defined(_TRACE_FSNOTIFY_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FSNOTIFY_H
+
+#include <linux/tracepoint.h>
+
+#include <trace/misc/fsnotify.h>
+
+TRACE_EVENT(fsnotify,
+	TP_PROTO(__u32 mask, const void *data, int data_type,
+		 struct inode *dir, const struct qstr *file_name,
+		 struct inode *inode, u32 cookie),
+
+	TP_ARGS(mask, data, data_type, dir, file_name, inode, cookie),
+
+	TP_STRUCT__entry(
+		__field(__u32, mask)
+		__field(unsigned long, dir_ino)
+		__field(unsigned long, ino)
+		__field(dev_t, s_dev)
+		__field(int, data_type)
+		__field(u32, cookie)
+		__string(file_name, file_name ? (const char *)file_name->name : "")
+	),
+
+	TP_fast_assign(
+		__entry->mask = mask;
+		__entry->dir_ino = dir ? dir->i_ino : 0;
+		__entry->ino = inode ? inode->i_ino : 0;
+		__entry->s_dev = dir ? dir->i_sb->s_dev :
+				 inode ? inode->i_sb->s_dev : 0;
+		__entry->data_type = data_type;
+		__entry->cookie = cookie;
+		__assign_str(file_name);
+	),
+
+	TP_printk("dev=%d:%d dir=%lu ino=%lu data_type=%d cookie=0x%x mask=0x%x %s name=%s",
+		  MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
+		  __entry->dir_ino, __entry->ino,
+		  __entry->data_type, __entry->cookie,
+		  __entry->mask, show_fsnotify_mask(__entry->mask),
+		  __get_str(file_name))
+);
+
+#endif /* _TRACE_FSNOTIFY_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>