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, 67 insertions, 0 deletions

diff --git a/fs/fuse/args.h b/fs/fuse/args.h
new file mode 100644
index 000000000..5173264a1
--- /dev/null
+++ b/fs/fuse/args.h
@@ -0,0 +1,67 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _FS_FUSE_ARGS_H
+#define _FS_FUSE_ARGS_H
+
+#include <linux/types.h>
+
+struct fuse_mount;
+
+/** One input argument of a request */
+struct fuse_in_arg {
+	unsigned size;
+	const void *value;
+};
+
+/** One output argument of a request */
+struct fuse_arg {
+	unsigned size;
+	void *value;
+};
+
+struct fuse_args {
+	u64 nodeid;
+	u32 opcode;
+	u32 uid;
+	u32 gid;
+	u32 pid;
+	u8 in_numargs;
+	u8 out_numargs;
+	u8 ext_idx;
+	bool force:1;
+	bool noreply:1;
+	bool nocreds:1;
+	bool in_pages:1;
+	bool out_pages:1;
+	bool user_pages:1;
+	bool out_argvar:1;
+	bool page_zeroing:1;
+	bool page_replace:1;
+	bool may_block:1;
+	bool is_ext:1;
+	bool is_pinned:1;
+	bool invalidate_vmap:1;
+	bool abort_on_kill:1;
+	/* server requested io-uring zero-copy for this op */
+	bool zero_copy:1;
+	struct fuse_in_arg in_args[4];
+	struct fuse_arg out_args[2];
+	void (*end)(struct fuse_args *args, int error);
+	/* Used for kvec iter backed by vmalloc address */
+	void *vmap_base;
+};
+
+/** FUSE folio descriptor */
+struct fuse_folio_desc {
+	unsigned int length;
+	unsigned int offset;
+};
+
+struct fuse_args_pages {
+	struct fuse_args args;
+	struct folio **folios;
+	struct fuse_folio_desc *descs;
+	unsigned int num_folios;
+};
+
+#endif /* _FS_FUSE_ARGS_H */