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, 134 insertions, 0 deletions

diff --git a/lib/uuid.c b/lib/uuid.c
new file mode 100644
index 000000000..128a51f18
--- /dev/null
+++ b/lib/uuid.c
@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Unified UUID/GUID definition
+ *
+ * Copyright (C) 2009, 2016 Intel Corp.
+ *	Huang Ying <ying.huang@intel.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/ctype.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/hex.h>
+#include <linux/uuid.h>
+#include <linux/random.h>
+
+const guid_t guid_null;
+EXPORT_SYMBOL(guid_null);
+const uuid_t uuid_null;
+EXPORT_SYMBOL(uuid_null);
+
+const u8 guid_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15};
+const u8 uuid_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
+
+/**
+ * generate_random_uuid - generate a random UUID
+ * @uuid: where to put the generated UUID
+ *
+ * Random UUID interface
+ *
+ * Used to create a Boot ID or a filesystem UUID/GUID, but can be
+ * useful for other kernel drivers.
+ */
+void generate_random_uuid(unsigned char uuid[16])
+{
+	get_random_bytes(uuid, 16);
+	/* Set UUID version to 4 --- truly random generation */
+	uuid[6] = (uuid[6] & 0x0F) | 0x40;
+	/* Set the UUID variant to DCE */
+	uuid[8] = (uuid[8] & 0x3F) | 0x80;
+}
+EXPORT_SYMBOL(generate_random_uuid);
+
+void generate_random_guid(unsigned char guid[16])
+{
+	get_random_bytes(guid, 16);
+	/* Set GUID version to 4 --- truly random generation */
+	guid[7] = (guid[7] & 0x0F) | 0x40;
+	/* Set the GUID variant to DCE */
+	guid[8] = (guid[8] & 0x3F) | 0x80;
+}
+EXPORT_SYMBOL(generate_random_guid);
+
+static void __uuid_gen_common(__u8 b[16])
+{
+	get_random_bytes(b, 16);
+	/* revision 0b10 */
+	b[8] = (b[8] & 0x3F) | 0x80;
+}
+
+void guid_gen(guid_t *lu)
+{
+	__uuid_gen_common(lu->b);
+	/* version 4 : random generation */
+	lu->b[7] = (lu->b[7] & 0x0F) | 0x40;
+}
+EXPORT_SYMBOL_GPL(guid_gen);
+
+void uuid_gen(uuid_t *bu)
+{
+	__uuid_gen_common(bu->b);
+	/* version 4 : random generation */
+	bu->b[6] = (bu->b[6] & 0x0F) | 0x40;
+}
+EXPORT_SYMBOL_GPL(uuid_gen);
+
+/**
+ * uuid_is_valid - checks if a UUID string is valid
+ * @uuid:	UUID string to check
+ *
+ * Description:
+ * It checks if the UUID string is following the format:
+ *	xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
+ *
+ * where x is a hex digit.
+ *
+ * Return: true if input is valid UUID string.
+ */
+bool uuid_is_valid(const char *uuid)
+{
+	unsigned int i;
+
+	for (i = 0; i < UUID_STRING_LEN; i++) {
+		if (i == 8 || i == 13 || i == 18 || i == 23) {
+			if (uuid[i] != '-')
+				return false;
+		} else if (!isxdigit(uuid[i])) {
+			return false;
+		}
+	}
+
+	return true;
+}
+EXPORT_SYMBOL(uuid_is_valid);
+
+static int __uuid_parse(const char *uuid, __u8 b[16], const u8 ei[16])
+{
+	static const u8 si[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34};
+	unsigned int i;
+
+	if (!uuid_is_valid(uuid))
+		return -EINVAL;
+
+	for (i = 0; i < 16; i++) {
+		int hi = hex_to_bin(uuid[si[i] + 0]);
+		int lo = hex_to_bin(uuid[si[i] + 1]);
+
+		b[ei[i]] = (hi << 4) | lo;
+	}
+
+	return 0;
+}
+
+int guid_parse(const char *uuid, guid_t *u)
+{
+	return __uuid_parse(uuid, u->b, guid_index);
+}
+EXPORT_SYMBOL(guid_parse);
+
+int uuid_parse(const char *uuid, uuid_t *u)
+{
+	return __uuid_parse(uuid, u->b, uuid_index);
+}
+EXPORT_SYMBOL(uuid_parse);