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, 28 insertions, 0 deletions

diff --git a/scripts/include/hash.h b/scripts/include/hash.h
new file mode 100644
index 000000000..efa904368
--- /dev/null
+++ b/scripts/include/hash.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef HASH_H
+#define HASH_H
+
+static inline unsigned int hash_str(const char *s)
+{
+	/* fnv32 hash */
+	unsigned int hash = 2166136261U;
+
+	for (; *s; s++)
+		hash = (hash ^ *s) * 0x01000193;
+	return hash;
+}
+
+/* simplified version of functions from include/linux/hash.h */
+#define GOLDEN_RATIO_32 0x61C88647
+
+static inline unsigned int hash_32(unsigned int val)
+{
+	return 0x61C88647 * val;
+}
+
+static inline unsigned int hash_ptr(const void *ptr)
+{
+	return hash_32((unsigned int)(unsigned long)ptr);
+}
+
+#endif /* HASH_H */