Commit a2d0b503 authored by Namjae Jeon's avatar Namjae Jeon
Browse files

cifsd: add the check to prevent potential overflow with smb_strtoUTF16() and UNICODE_LEN() 



Add the check to prevent potential overflow with smb_strtoUTF16() and
UNICODE_LEN().

Reviewed-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 70478059

fs/cifsd/auth.c

+31 −19
Original line number Diff line number Diff line
@@ -246,7 +246,7 @@ static int ksmbd_gen_sess_key(struct ksmbd_session *sess, char *hash, 
static int calc_ntlmv2_hash(struct ksmbd_session *sess, char *ntlmv2_hash,

		char *dname)

{

	int ret, len;

	int ret, len, conv_len;

	wchar_t *domain = NULL;

	__le16 *uniname = NULL;

	struct ksmbd_crypto_ctx *ctx;
@@ -279,15 +279,17 @@ static int calc_ntlmv2_hash(struct ksmbd_session *sess, char *ntlmv2_hash, 
		goto out;

	}



	if (len) {

		len = smb_strtoUTF16(uniname, user_name(sess->user), len,

	conv_len = smb_strtoUTF16(uniname, user_name(sess->user), len,

			sess->conn->local_nls);

		UniStrupr(uniname);

	if (conv_len < 0 || conv_len > len) {

		ret = -EINVAL;

		goto out;

	}

	UniStrupr(uniname);



	ret = crypto_shash_update(CRYPTO_HMACMD5(ctx),

				  (char *)uniname,

				  UNICODE_LEN(len));

				  UNICODE_LEN(conv_len));

	if (ret) {

		ksmbd_debug(AUTH, "Could not update with user\n");

		goto out;
@@ -301,12 +303,16 @@ static int calc_ntlmv2_hash(struct ksmbd_session *sess, char *ntlmv2_hash, 
		goto out;

	}



	len = smb_strtoUTF16((__le16 *)domain, dname, len,

	conv_len = smb_strtoUTF16((__le16 *)domain, dname, len,

			     sess->conn->local_nls);

	if (conv_len < 0 || conv_len > len) {

		ret = -EINVAL;

		goto out;

	}



	ret = crypto_shash_update(CRYPTO_HMACMD5(ctx),

				  (char *)domain,

				  UNICODE_LEN(len));

				  UNICODE_LEN(conv_len));

	if (ret) {

		ksmbd_debug(AUTH, "Could not update with domain\n");

		goto out;
@@ -584,6 +590,7 @@ ksmbd_build_ntlmssp_challenge_blob(struct challenge_message *chgblob, 
	wchar_t *name;

	__u8 *target_name;

	unsigned int len, flags, blob_off, blob_len, type, target_info_len = 0;

	unsigned int uni_len, conv_len;

	int cflags = sess->ntlmssp.client_flags;



	memcpy(chgblob->Signature, NTLMSSP_SIGNATURE, 8);
@@ -611,19 +618,24 @@ ksmbd_build_ntlmssp_challenge_blob(struct challenge_message *chgblob, 


	chgblob->NegotiateFlags = cpu_to_le32(flags);

	len = strlen(ksmbd_netbios_name());

	name = kmalloc(2 + (len * 2), GFP_KERNEL);

	name = kmalloc(2 + UNICODE_LEN(len), GFP_KERNEL);

	if (!name)

		return -ENOMEM;



	len = smb_strtoUTF16((__le16 *)name, ksmbd_netbios_name(), len,

	conv_len = smb_strtoUTF16((__le16 *)name, ksmbd_netbios_name(), len,

			sess->conn->local_nls);

	len = UNICODE_LEN(len);

	if (conv_len < 0 || conv_len > len) {

		kfree(name);

		return -EINVAL;

	}



	uni_len = UNICODE_LEN(conv_len);



	blob_off = sizeof(struct challenge_message);

	blob_len = blob_off + len;

	blob_len = blob_off + uni_len;



	chgblob->TargetName.Length = cpu_to_le16(len);

	chgblob->TargetName.MaximumLength = cpu_to_le16(len);

	chgblob->TargetName.Length = cpu_to_le16(uni_len);

	chgblob->TargetName.MaximumLength = cpu_to_le16(uni_len);

	chgblob->TargetName.BufferOffset = cpu_to_le32(blob_off);



	/* Initialize random conn challenge */
@@ -635,18 +647,18 @@ ksmbd_build_ntlmssp_challenge_blob(struct challenge_message *chgblob, 
	chgblob->TargetInfoArray.BufferOffset = cpu_to_le32(blob_len);



	target_name = (__u8 *)chgblob + blob_off;

	memcpy(target_name, name, len);

	tinfo = (struct target_info *)(target_name + len);

	memcpy(target_name, name, uni_len);

	tinfo = (struct target_info *)(target_name + uni_len);



	chgblob->TargetInfoArray.Length = 0;

	/* Add target info list for NetBIOS/DNS settings */

	for (type = NTLMSSP_AV_NB_COMPUTER_NAME;

	     type <= NTLMSSP_AV_DNS_DOMAIN_NAME; type++) {

		tinfo->Type = cpu_to_le16(type);

		tinfo->Length = cpu_to_le16(len);

		memcpy(tinfo->Content, name, len);

		tinfo = (struct target_info *)((char *)tinfo + 4 + len);

		target_info_len += 4 + len;

		tinfo->Length = cpu_to_le16(uni_len);

		memcpy(tinfo->Content, name, uni_len);

		tinfo = (struct target_info *)((char *)tinfo + 4 + uni_len);

		target_info_len += 4 + uni_len;

	}



	/* Add terminator subblock */