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, 39 insertions, 0 deletions

diff --git a/fs/lockd/share.h b/fs/lockd/share.h
new file mode 100644
index 000000000..a12b6c454
--- /dev/null
+++ b/fs/lockd/share.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * DOS share management for lockd.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef _LOCKD_SHARE_H
+#define _LOCKD_SHARE_H
+
+#include <linux/bits.h>
+
+/* Synthetic svid for lockowner lookup during share operations */
+#define LOCKD_SHARE_SVID	(~(u32)0)
+
+/* One bit per (access, deny) pair; index = (access << 2) | deny */
+#define LOCKD_FSH_BIT(a, d)	BIT(((a) << 2) | (d))
+
+/*
+ * DOS share for a specific file
+ */
+struct lockd_share {
+	struct lockd_share *	s_next;		/* linked list */
+	struct nlm_host *	s_host;		/* client host */
+	struct nlm_file *	s_file;		/* shared file */
+	struct xdr_netobj	s_owner;	/* owner handle */
+	u32			s_access;	/* access mode */
+	u32			s_mode;		/* deny mode */
+	u16			s_access_deny_bmap;	/* held (access, deny) pairs */
+};
+
+__be32	nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file,
+			  struct xdr_netobj *oh, u32 access, u32 mode);
+__be32	nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file,
+			    struct xdr_netobj *oh, u32 access, u32 mode);
+void	nlmsvc_traverse_shares(struct nlm_host *, struct nlm_file *,
+					       nlm_host_match_fn_t);
+
+#endif /* _LOCKD_SHARE_H */