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, 47 insertions, 0 deletions

diff --git a/security/selinux/include/hash.h b/security/selinux/include/hash.h
new file mode 100644
index 000000000..18956dbef
--- /dev/null
+++ b/security/selinux/include/hash.h
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef _SELINUX_HASH_H_
+#define _SELINUX_HASH_H_
+
+/*
+ * Based on MurmurHash3, written by Austin Appleby and placed in the
+ * public domain.
+ */
+static inline u32 av_hash(u32 key1, u32 key2, u32 key3, u32 mask)
+{
+	static const u32 c1 = 0xcc9e2d51;
+	static const u32 c2 = 0x1b873593;
+	static const u32 r1 = 15;
+	static const u32 r2 = 13;
+	static const u32 m = 5;
+	static const u32 n = 0xe6546b64;
+
+	u32 hash = 0;
+
+#define mix(input)                                         \
+	do {                                               \
+		u32 v = input;                             \
+		v *= c1;                                   \
+		v = (v << r1) | (v >> (32 - r1));          \
+		v *= c2;                                   \
+		hash ^= v;                                 \
+		hash = (hash << r2) | (hash >> (32 - r2)); \
+		hash = hash * m + n;                       \
+	} while (0)
+
+	mix(key1);
+	mix(key2);
+	mix(key3);
+
+#undef mix
+
+	hash ^= hash >> 16;
+	hash *= 0x85ebca6b;
+	hash ^= hash >> 13;
+	hash *= 0xc2b2ae35;
+	hash ^= hash >> 16;
+
+	return hash & mask;
+}
+
+#endif /* _SELINUX_HASH_H_ */