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, 26 insertions, 0 deletions

diff --git a/include/drm/clients/drm_client_setup.h b/include/drm/clients/drm_client_setup.h
new file mode 100644
index 000000000..46aab3fb4
--- /dev/null
+++ b/include/drm/clients/drm_client_setup.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: MIT */
+
+#ifndef DRM_CLIENT_SETUP_H
+#define DRM_CLIENT_SETUP_H
+
+#include <linux/types.h>
+
+struct drm_device;
+struct drm_format_info;
+
+#if defined(CONFIG_DRM_CLIENT_SETUP)
+void drm_client_setup(struct drm_device *dev, const struct drm_format_info *format);
+void drm_client_setup_with_fourcc(struct drm_device *dev, u32 fourcc);
+void drm_client_setup_with_color_mode(struct drm_device *dev, unsigned int color_mode);
+#else
+static inline void drm_client_setup(struct drm_device *dev,
+				    const struct drm_format_info *format)
+{ }
+static inline void drm_client_setup_with_fourcc(struct drm_device *dev, u32 fourcc)
+{ }
+static inline void drm_client_setup_with_color_mode(struct drm_device *dev,
+						    unsigned int color_mode)
+{ }
+#endif
+
+#endif