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, 22 insertions, 0 deletions

diff --git a/samples/vfio-mdev/mdpy-defs.h b/samples/vfio-mdev/mdpy-defs.h
new file mode 100644
index 000000000..961c55ec3
--- /dev/null
+++ b/samples/vfio-mdev/mdpy-defs.h
@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Simple pci display device.
+ *
+ * Framebuffer memory is pci bar 0.
+ * Configuration (read-only) is in pci config space.
+ * Format field uses drm fourcc codes.
+ * ATM only DRM_FORMAT_XRGB8888 is supported.
+ */
+
+/* pci ids */
+#define MDPY_PCI_VENDOR_ID	PCI_VENDOR_ID_REDHAT
+#define MDPY_PCI_DEVICE_ID	0x000f
+#define MDPY_PCI_SUBVENDOR_ID	PCI_SUBVENDOR_ID_REDHAT_QUMRANET
+#define MDPY_PCI_SUBDEVICE_ID	PCI_SUBDEVICE_ID_QEMU
+
+/* pci cfg space offsets for fb config (dword) */
+#define MDPY_VENDORCAP_OFFSET   0x40
+#define MDPY_VENDORCAP_SIZE     0x10
+#define MDPY_FORMAT_OFFSET	(MDPY_VENDORCAP_OFFSET + 0x04)
+#define MDPY_WIDTH_OFFSET	(MDPY_VENDORCAP_OFFSET + 0x08)
+#define MDPY_HEIGHT_OFFSET	(MDPY_VENDORCAP_OFFSET + 0x0c)