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, 89 insertions, 0 deletions

diff --git a/fs/ecryptfs/debug.c b/fs/ecryptfs/debug.c
new file mode 100644
index 000000000..426437024
--- /dev/null
+++ b/fs/ecryptfs/debug.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * eCryptfs: Linux filesystem encryption layer
+ * Functions only useful for debugging.
+ *
+ * Copyright (C) 2006 International Business Machines Corp.
+ *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
+ */
+
+#include <linux/string.h>
+#include "ecryptfs_kernel.h"
+
+/*
+ * ecryptfs_dump_auth_tok - debug function to print auth toks
+ *
+ * This function will print the contents of an ecryptfs authentication
+ * token.
+ */
+void ecryptfs_dump_auth_tok(struct ecryptfs_auth_tok *auth_tok)
+{
+	char salt[ECRYPTFS_SALT_SIZE * 2 + 1];
+	char sig[ECRYPTFS_SIG_SIZE_HEX + 1];
+
+	ecryptfs_printk(KERN_DEBUG, "Auth tok at mem loc [%p]:\n",
+			auth_tok);
+	if (auth_tok->flags & ECRYPTFS_PRIVATE_KEY) {
+		ecryptfs_printk(KERN_DEBUG, " * private key type\n");
+	} else {
+		ecryptfs_printk(KERN_DEBUG, " * passphrase type\n");
+		ecryptfs_to_hex(salt, auth_tok->token.password.salt,
+				ECRYPTFS_SALT_SIZE);
+		ecryptfs_printk(KERN_DEBUG, " * salt = [%s]\n", salt);
+		if (auth_tok->token.password.flags &
+		    ECRYPTFS_PERSISTENT_PASSWORD) {
+			ecryptfs_printk(KERN_DEBUG, " * persistent\n");
+		}
+		strscpy(sig, auth_tok->token.password.signature);
+		ecryptfs_printk(KERN_DEBUG, " * signature = [%s]\n", sig);
+	}
+	ecryptfs_printk(KERN_DEBUG, " * session_key.flags = [0x%x]\n",
+			auth_tok->session_key.flags);
+	if (auth_tok->session_key.flags
+	    & ECRYPTFS_USERSPACE_SHOULD_TRY_TO_DECRYPT)
+		ecryptfs_printk(KERN_DEBUG,
+				" * Userspace decrypt request set\n");
+	if (auth_tok->session_key.flags
+	    & ECRYPTFS_USERSPACE_SHOULD_TRY_TO_ENCRYPT)
+		ecryptfs_printk(KERN_DEBUG,
+				" * Userspace encrypt request set\n");
+	if (auth_tok->session_key.flags & ECRYPTFS_CONTAINS_DECRYPTED_KEY) {
+		ecryptfs_printk(KERN_DEBUG, " * Contains decrypted key\n");
+		ecryptfs_printk(KERN_DEBUG,
+				" * session_key.decrypted_key_size = [0x%x]\n",
+				auth_tok->session_key.decrypted_key_size);
+		ecryptfs_printk(KERN_DEBUG, " * Decrypted session key "
+				"dump:\n");
+		if (ecryptfs_verbosity > 0)
+			ecryptfs_dump_hex(auth_tok->session_key.decrypted_key,
+					  ECRYPTFS_DEFAULT_KEY_BYTES);
+	}
+	if (auth_tok->session_key.flags & ECRYPTFS_CONTAINS_ENCRYPTED_KEY) {
+		ecryptfs_printk(KERN_DEBUG, " * Contains encrypted key\n");
+		ecryptfs_printk(KERN_DEBUG,
+				" * session_key.encrypted_key_size = [0x%x]\n",
+				auth_tok->session_key.encrypted_key_size);
+		ecryptfs_printk(KERN_DEBUG, " * Encrypted session key "
+				"dump:\n");
+		if (ecryptfs_verbosity > 0)
+			ecryptfs_dump_hex(auth_tok->session_key.encrypted_key,
+					  auth_tok->session_key.
+					  encrypted_key_size);
+	}
+}
+
+/**
+ * ecryptfs_dump_hex - debug hex printer
+ * @data: string of bytes to be printed
+ * @bytes: number of bytes to print
+ *
+ * Dump hexadecimal representation of char array
+ */
+void ecryptfs_dump_hex(char *data, int bytes)
+{
+	if (ecryptfs_verbosity < 1)
+		return;
+
+	print_hex_dump(KERN_DEBUG, "ecryptfs: ", DUMP_PREFIX_OFFSET, 16, 1,
+		       data, bytes, false);
+}