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, 25 insertions, 0 deletions

diff --git a/fs/smb/client/smb1debug.c b/fs/smb/client/smb1debug.c
new file mode 100644
index 000000000..e2d013e75
--- /dev/null
+++ b/fs/smb/client/smb1debug.c
@@ -0,0 +1,25 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ *   Copyright (C) International Business Machines  Corp., 2000,2005
+ *
+ *   Modified by Steve French (sfrench@us.ibm.com)
+ */
+#include "cifsproto.h"
+#include "smb1proto.h"
+#include "cifs_debug.h"
+
+void cifs_dump_detail(void *buf, size_t buf_len, struct TCP_Server_Info *server)
+{
+#ifdef CONFIG_CIFS_DEBUG2
+	struct smb_hdr *smb = buf;
+
+	cifs_dbg(VFS, "Cmd: %d Err: 0x%x Flags: 0x%x Flgs2: 0x%x Mid: %d Pid: %d Wct: %d\n",
+		 smb->Command, smb->Status.CifsError, smb->Flags,
+		 smb->Flags2, smb->Mid, smb->Pid, smb->WordCount);
+	if (!server->ops->check_message(buf, buf_len, server->total_read, server)) {
+		cifs_dbg(VFS, "smb buf %p len %u\n", smb,
+			 server->ops->calc_smb_size(smb));
+	}
+#endif /* CONFIG_CIFS_DEBUG2 */
+}