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, 34 insertions, 0 deletions

diff --git a/samples/bpf/net_shared.h b/samples/bpf/net_shared.h
new file mode 100644
index 000000000..88cc52461
--- /dev/null
+++ b/samples/bpf/net_shared.h
@@ -0,0 +1,34 @@
+// SPDX-License-Identifier: GPL-2.0
+#ifndef _NET_SHARED_H
+#define _NET_SHARED_H
+
+#define AF_INET		2
+#define AF_INET6	10
+
+#define ETH_ALEN 6
+#define ETH_P_802_3_MIN 0x0600
+#define ETH_P_8021Q 0x8100
+#define ETH_P_8021AD 0x88A8
+#define ETH_P_IP 0x0800
+#define ETH_P_IPV6 0x86DD
+#define ETH_P_ARP 0x0806
+#define IPPROTO_ICMPV6 58
+
+#define TC_ACT_OK		0
+#define TC_ACT_SHOT		2
+
+#define IFNAMSIZ 16
+
+#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && \
+	__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+#define bpf_ntohs(x)		__builtin_bswap16(x)
+#define bpf_htons(x)		__builtin_bswap16(x)
+#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && \
+	__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#define bpf_ntohs(x)		(x)
+#define bpf_htons(x)		(x)
+#else
+# error "Endianness detection needs to be set up for your compiler?!"
+#endif
+
+#endif