Merge tag '5.15-rc3-ksmbd-fixes' of git://git.samba.org/ksmbd

Pull ksmbd server fixes from Steve French:
 "Eleven fixes for the ksmbd kernel server, mostly security related:

   - an important fix for disabling weak NTLMv1 authentication

   - seven security (improved buffer overflow checks) fixes

   - fix for wrong infolevel struct used in some getattr/setattr paths

   - two small documentation fixes"

* tag '5.15-rc3-ksmbd-fixes' of git://git.samba.org/ksmbd:
  ksmbd: missing check for NULL in convert_to_nt_pathname()
  ksmbd: fix transform header validation
  ksmbd: add buffer validation for SMB2_CREATE_CONTEXT
  ksmbd: add validation in smb2 negotiate
  ksmbd: add request buffer validation in smb2_set_info
  ksmbd: use correct basic info level in set_file_basic_info()
  ksmbd: remove NTLMv1 authentication
  ksmbd: fix documentation for 2 functions
  MAINTAINERS: rename cifs_common to smbfs_common in cifs and ksmbd entry
  ksmbd: fix invalid request buffer access in compound
  ksmbd: remove RFC1002 check in smb2 request

MAINTAINERS

@@ -4657,7 +4657,7 @@ W:	http://linux-cifs.samba.org/
 T:	git git://git.samba.org/sfrench/cifs-2.6.git
 F:	Documentation/admin-guide/cifs/
 F:	fs/cifs/
-F:	fs/cifs_common/
+F:	fs/smbfs_common/
 
 COMPACTPCI HOTPLUG CORE
 M:	Scott Murray <scott@spiteful.org>
@@ -10195,8 +10195,8 @@ M:	Hyunchul Lee <hyc.lee@gmail.com>
 L:	linux-cifs@vger.kernel.org
 S:	Maintained
 T:	git git://git.samba.org/ksmbd.git
-F:	fs/cifs_common/
 F:	fs/ksmbd/
+F:	fs/smbfs_common/
 
 KERNEL UNIT TESTING FRAMEWORK (KUnit)
 M:	Brendan Higgins <brendanhiggins@google.com>

fs/ksmbd/auth.c

@@ -68,125 +68,6 @@ void ksmbd_copy_gss_neg_header(void *buf)
 	memcpy(buf, NEGOTIATE_GSS_HEADER, AUTH_GSS_LENGTH);
 }
 
-static void
-str_to_key(unsigned char *str, unsigned char *key)
-{
-	int i;
-
-	key[0] = str[0] >> 1;
-	key[1] = ((str[0] & 0x01) << 6) | (str[1] >> 2);
-	key[2] = ((str[1] & 0x03) << 5) | (str[2] >> 3);
-	key[3] = ((str[2] & 0x07) << 4) | (str[3] >> 4);
-	key[4] = ((str[3] & 0x0F) << 3) | (str[4] >> 5);
-	key[5] = ((str[4] & 0x1F) << 2) | (str[5] >> 6);
-	key[6] = ((str[5] & 0x3F) << 1) | (str[6] >> 7);
-	key[7] = str[6] & 0x7F;
-	for (i = 0; i < 8; i++)
-		key[i] = (key[i] << 1);
-}
-
-static int
-smbhash(unsigned char *out, const unsigned char *in, unsigned char *key)
-{
-	unsigned char key2[8];
-	struct des_ctx ctx;
-
-	if (fips_enabled) {
-		ksmbd_debug(AUTH, "FIPS compliance enabled: DES not permitted\n");
-		return -ENOENT;
-	}
-
-	str_to_key(key, key2);
-	des_expand_key(&ctx, key2, DES_KEY_SIZE);
-	des_encrypt(&ctx, out, in);
-	memzero_explicit(&ctx, sizeof(ctx));
-	return 0;
-}
-
-static int ksmbd_enc_p24(unsigned char *p21, const unsigned char *c8, unsigned char *p24)
-{
-	int rc;
-
-	rc = smbhash(p24, c8, p21);
-	if (rc)
-		return rc;
-	rc = smbhash(p24 + 8, c8, p21 + 7);
-	if (rc)
-		return rc;
-	return smbhash(p24 + 16, c8, p21 + 14);
-}
-
-/* produce a md4 message digest from data of length n bytes */
-static int ksmbd_enc_md4(unsigned char *md4_hash, unsigned char *link_str,
-			 int link_len)
-{
-	int rc;
-	struct ksmbd_crypto_ctx *ctx;
-
-	ctx = ksmbd_crypto_ctx_find_md4();
-	if (!ctx) {
-		ksmbd_debug(AUTH, "Crypto md4 allocation error\n");
-		return -ENOMEM;
-	}
-
-	rc = crypto_shash_init(CRYPTO_MD4(ctx));
-	if (rc) {
-		ksmbd_debug(AUTH, "Could not init md4 shash\n");
-		goto out;
-	}
-
-	rc = crypto_shash_update(CRYPTO_MD4(ctx), link_str, link_len);
-	if (rc) {
-		ksmbd_debug(AUTH, "Could not update with link_str\n");
-		goto out;
-	}
-
-	rc = crypto_shash_final(CRYPTO_MD4(ctx), md4_hash);
-	if (rc)
-		ksmbd_debug(AUTH, "Could not generate md4 hash\n");
-out:
-	ksmbd_release_crypto_ctx(ctx);
-	return rc;
-}
-
-static int ksmbd_enc_update_sess_key(unsigned char *md5_hash, char *nonce,
-				     char *server_challenge, int len)
-{
-	int rc;
-	struct ksmbd_crypto_ctx *ctx;
-
-	ctx = ksmbd_crypto_ctx_find_md5();
-	if (!ctx) {
-		ksmbd_debug(AUTH, "Crypto md5 allocation error\n");
-		return -ENOMEM;
-	}
-
-	rc = crypto_shash_init(CRYPTO_MD5(ctx));
-	if (rc) {
-		ksmbd_debug(AUTH, "Could not init md5 shash\n");
-		goto out;
-	}
-
-	rc = crypto_shash_update(CRYPTO_MD5(ctx), server_challenge, len);
-	if (rc) {
-		ksmbd_debug(AUTH, "Could not update with challenge\n");
-		goto out;
-	}
-
-	rc = crypto_shash_update(CRYPTO_MD5(ctx), nonce, len);
-	if (rc) {
-		ksmbd_debug(AUTH, "Could not update with nonce\n");
-		goto out;
-	}
-
-	rc = crypto_shash_final(CRYPTO_MD5(ctx), md5_hash);
-	if (rc)
-		ksmbd_debug(AUTH, "Could not generate md5 hash\n");
-out:
-	ksmbd_release_crypto_ctx(ctx);
-	return rc;
-}
-
 /**
  * ksmbd_gen_sess_key() - function to generate session key
  * @sess:	session of connection
@@ -324,43 +205,6 @@ static int calc_ntlmv2_hash(struct ksmbd_session *sess, char *ntlmv2_hash,
 	return ret;
 }
 
-/**
- * ksmbd_auth_ntlm() - NTLM authentication handler
- * @sess:	session of connection
- * @pw_buf:	NTLM challenge response
- * @passkey:	user password
- *
- * Return:	0 on success, error number on error
- */
-int ksmbd_auth_ntlm(struct ksmbd_session *sess, char *pw_buf)
-{
-	int rc;
-	unsigned char p21[21];
-	char key[CIFS_AUTH_RESP_SIZE];
-
-	memset(p21, '\0', 21);
-	memcpy(p21, user_passkey(sess->user), CIFS_NTHASH_SIZE);
-	rc = ksmbd_enc_p24(p21, sess->ntlmssp.cryptkey, key);
-	if (rc) {
-		pr_err("password processing failed\n");
-		return rc;
-	}
-
-	ksmbd_enc_md4(sess->sess_key, user_passkey(sess->user),
-		      CIFS_SMB1_SESSKEY_SIZE);
-	memcpy(sess->sess_key + CIFS_SMB1_SESSKEY_SIZE, key,
-	       CIFS_AUTH_RESP_SIZE);
-	sess->sequence_number = 1;
-
-	if (strncmp(pw_buf, key, CIFS_AUTH_RESP_SIZE) != 0) {
-		ksmbd_debug(AUTH, "ntlmv1 authentication failed\n");
-		return -EINVAL;
-	}
-
-	ksmbd_debug(AUTH, "ntlmv1 authentication pass\n");
-	return 0;
-}
-
 /**
  * ksmbd_auth_ntlmv2() - NTLMv2 authentication handler
  * @sess:	session of connection
@@ -441,44 +285,6 @@ int ksmbd_auth_ntlmv2(struct ksmbd_session *sess, struct ntlmv2_resp *ntlmv2,
 	return rc;
 }
 
-/**
- * __ksmbd_auth_ntlmv2() - NTLM2(extended security) authentication handler
- * @sess:	session of connection
- * @client_nonce:	client nonce from LM response.
- * @ntlm_resp:		ntlm response data from client.
- *
- * Return:	0 on success, error number on error
- */
-static int __ksmbd_auth_ntlmv2(struct ksmbd_session *sess, char *client_nonce,
-			       char *ntlm_resp)
-{
-	char sess_key[CIFS_SMB1_SESSKEY_SIZE] = {0};
-	int rc;
-	unsigned char p21[21];
-	char key[CIFS_AUTH_RESP_SIZE];
-
-	rc = ksmbd_enc_update_sess_key(sess_key,
-				       client_nonce,
-				       (char *)sess->ntlmssp.cryptkey, 8);
-	if (rc) {
-		pr_err("password processing failed\n");
-		goto out;
-	}
-
-	memset(p21, '\0', 21);
-	memcpy(p21, user_passkey(sess->user), CIFS_NTHASH_SIZE);
-	rc = ksmbd_enc_p24(p21, sess_key, key);
-	if (rc) {
-		pr_err("password processing failed\n");
-		goto out;
-	}
-
-	if (memcmp(ntlm_resp, key, CIFS_AUTH_RESP_SIZE) != 0)
-		rc = -EINVAL;
-out:
-	return rc;
-}
-
 /**
  * ksmbd_decode_ntlmssp_auth_blob() - helper function to construct
  * authenticate blob
@@ -512,17 +318,6 @@ int ksmbd_decode_ntlmssp_auth_blob(struct authenticate_message *authblob,
 	nt_off = le32_to_cpu(authblob->NtChallengeResponse.BufferOffset);
 	nt_len = le16_to_cpu(authblob->NtChallengeResponse.Length);
 
-	/* process NTLM authentication */
-	if (nt_len == CIFS_AUTH_RESP_SIZE) {
-		if (le32_to_cpu(authblob->NegotiateFlags) &
-		    NTLMSSP_NEGOTIATE_EXTENDED_SEC)
-			return __ksmbd_auth_ntlmv2(sess, (char *)authblob +
-				lm_off, (char *)authblob + nt_off);
-		else
-			return ksmbd_auth_ntlm(sess, (char *)authblob +
-				nt_off);
-	}
-
 	/* TODO : use domain name that imported from configuration file */
 	domain_name = smb_strndup_from_utf16((const char *)authblob +
 			le32_to_cpu(authblob->DomainName.BufferOffset),

fs/ksmbd/crypto_ctx.c

@@ -81,12 +81,6 @@ static struct shash_desc *alloc_shash_desc(int id)
 	case CRYPTO_SHASH_SHA512:
 		tfm = crypto_alloc_shash("sha512", 0, 0);
 		break;
-	case CRYPTO_SHASH_MD4:
-		tfm = crypto_alloc_shash("md4", 0, 0);
-		break;
-	case CRYPTO_SHASH_MD5:
-		tfm = crypto_alloc_shash("md5", 0, 0);
-		break;
 	default:
 		return NULL;
 	}
@@ -214,16 +208,6 @@ struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_sha512(void)
 	return ____crypto_shash_ctx_find(CRYPTO_SHASH_SHA512);
 }
 
-struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_md4(void)
-{
-	return ____crypto_shash_ctx_find(CRYPTO_SHASH_MD4);
-}
-
-struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_md5(void)
-{
-	return ____crypto_shash_ctx_find(CRYPTO_SHASH_MD5);
-}
-
 static struct ksmbd_crypto_ctx *____crypto_aead_ctx_find(int id)
 {
 	struct ksmbd_crypto_ctx *ctx;

fs/ksmbd/crypto_ctx.h

@@ -15,8 +15,6 @@ enum {
 	CRYPTO_SHASH_CMACAES,
 	CRYPTO_SHASH_SHA256,
 	CRYPTO_SHASH_SHA512,
-	CRYPTO_SHASH_MD4,
-	CRYPTO_SHASH_MD5,
 	CRYPTO_SHASH_MAX,
 };
 
@@ -43,8 +41,6 @@ struct ksmbd_crypto_ctx {
 #define CRYPTO_CMACAES(c)	((c)->desc[CRYPTO_SHASH_CMACAES])
 #define CRYPTO_SHA256(c)	((c)->desc[CRYPTO_SHASH_SHA256])
 #define CRYPTO_SHA512(c)	((c)->desc[CRYPTO_SHASH_SHA512])
-#define CRYPTO_MD4(c)		((c)->desc[CRYPTO_SHASH_MD4])
-#define CRYPTO_MD5(c)		((c)->desc[CRYPTO_SHASH_MD5])
 
 #define CRYPTO_HMACMD5_TFM(c)	((c)->desc[CRYPTO_SHASH_HMACMD5]->tfm)
 #define CRYPTO_HMACSHA256_TFM(c)\
@@ -52,8 +48,6 @@ struct ksmbd_crypto_ctx {
 #define CRYPTO_CMACAES_TFM(c)	((c)->desc[CRYPTO_SHASH_CMACAES]->tfm)
 #define CRYPTO_SHA256_TFM(c)	((c)->desc[CRYPTO_SHASH_SHA256]->tfm)
 #define CRYPTO_SHA512_TFM(c)	((c)->desc[CRYPTO_SHASH_SHA512]->tfm)
-#define CRYPTO_MD4_TFM(c)	((c)->desc[CRYPTO_SHASH_MD4]->tfm)
-#define CRYPTO_MD5_TFM(c)	((c)->desc[CRYPTO_SHASH_MD5]->tfm)
 
 #define CRYPTO_GCM(c)		((c)->ccmaes[CRYPTO_AEAD_AES_GCM])
 #define CRYPTO_CCM(c)		((c)->ccmaes[CRYPTO_AEAD_AES_CCM])
@@ -64,8 +58,6 @@ struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_hmacsha256(void);
 struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_cmacaes(void);
 struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_sha512(void);
 struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_sha256(void);
-struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_md4(void);
-struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_md5(void);
 struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_gcm(void);
 struct ksmbd_crypto_ctx *ksmbd_crypto_ctx_find_ccm(void);
 void ksmbd_crypto_destroy(void);

fs/ksmbd/misc.c

@@ -162,17 +162,14 @@ char *convert_to_nt_pathname(char *filename)
 {
 	char *ab_pathname;
 
-	if (strlen(filename) == 0) {
-		ab_pathname = kmalloc(2, GFP_KERNEL);
-		ab_pathname[0] = '\\';
-		ab_pathname[1] = '\0';
-	} else {
-		ab_pathname = kstrdup(filename, GFP_KERNEL);
-		if (!ab_pathname)
-			return NULL;
+	if (strlen(filename) == 0)
+		filename = "\\";
 
-		ksmbd_conv_path_to_windows(ab_pathname);
-	}
+	ab_pathname = kstrdup(filename, GFP_KERNEL);
+	if (!ab_pathname)
+		return NULL;
+
+	ksmbd_conv_path_to_windows(ab_pathname);
 	return ab_pathname;
 }
 

fs/ksmbd/oplock.c

@@ -1451,26 +1451,47 @@ struct lease_ctx_info *parse_lease_state(void *open_req)
  */
 struct create_context *smb2_find_context_vals(void *open_req, const char *tag)
 {
-	char *data_offset;
 	struct create_context *cc;
 	unsigned int next = 0;
 	char *name;
 	struct smb2_create_req *req = (struct smb2_create_req *)open_req;
+	unsigned int remain_len, name_off, name_len, value_off, value_len,
+		     cc_len;
 
-	data_offset = (char *)req + 4 + le32_to_cpu(req->CreateContextsOffset);
-	cc = (struct create_context *)data_offset;
+	/*
+	 * CreateContextsOffset and CreateContextsLength are guaranteed to
+	 * be valid because of ksmbd_smb2_check_message().
+	 */
+	cc = (struct create_context *)((char *)req + 4 +
+				       le32_to_cpu(req->CreateContextsOffset));
+	remain_len = le32_to_cpu(req->CreateContextsLength);
 	do {
-		int val;
-
 		cc = (struct create_context *)((char *)cc + next);
-		name = le16_to_cpu(cc->NameOffset) + (char *)cc;
-		val = le16_to_cpu(cc->NameLength);
-		if (val < 4)
+		if (remain_len < offsetof(struct create_context, Buffer))
 			return ERR_PTR(-EINVAL);
 
-		if (memcmp(name, tag, val) == 0)
-			return cc;
 		next = le32_to_cpu(cc->Next);
+		name_off = le16_to_cpu(cc->NameOffset);
+		name_len = le16_to_cpu(cc->NameLength);
+		value_off = le16_to_cpu(cc->DataOffset);
+		value_len = le32_to_cpu(cc->DataLength);
+		cc_len = next ? next : remain_len;
+
+		if ((next & 0x7) != 0 ||
+		    next > remain_len ||
+		    name_off != offsetof(struct create_context, Buffer) ||
+		    name_len < 4 ||
+		    name_off + name_len > cc_len ||
+		    (value_off & 0x7) != 0 ||
+		    (value_off && (value_off < name_off + name_len)) ||
+		    ((u64)value_off + value_len > cc_len))
+			return ERR_PTR(-EINVAL);
+
+		name = (char *)cc + name_off;
+		if (memcmp(name, tag, name_len) == 0)
+			return cc;
+
+		remain_len -= next;
 	} while (next != 0);
 
 	return NULL;

fs/ksmbd/smb2pdu.h

@@ -1464,6 +1464,15 @@ struct smb2_file_all_info { /* data block encoding of response to level 18 */
 	char   FileName[1];
 } __packed; /* level 18 Query */
 
+struct smb2_file_basic_info { /* data block encoding of response to level 18 */
+	__le64 CreationTime;	/* Beginning of FILE_BASIC_INFO equivalent */
+	__le64 LastAccessTime;
+	__le64 LastWriteTime;
+	__le64 ChangeTime;
+	__le32 Attributes;
+	__u32  Pad1;		/* End of FILE_BASIC_INFO_INFO equivalent */
+} __packed;
+
 struct smb2_file_alt_name_info {
 	__le32 FileNameLength;
 	char FileName[0];

fs/ksmbd/smb_common.c

@@ -155,20 +155,7 @@ int ksmbd_verify_smb_message(struct ksmbd_work *work)
  */
 bool ksmbd_smb_request(struct ksmbd_conn *conn)
 {
-	int type = *(char *)conn->request_buf;
-
-	switch (type) {
-	case RFC1002_SESSION_MESSAGE:
-		/* Regular SMB request */
-		return true;
-	case RFC1002_SESSION_KEEP_ALIVE:
-		ksmbd_debug(SMB, "RFC 1002 session keep alive\n");
-		break;
-	default:
-		ksmbd_debug(SMB, "RFC 1002 unknown request type 0x%x\n", type);
-	}
-
-	return false;
+	return conn->request_buf[0] == 0;
 }
 
 static bool supported_protocol(int idx)
@@ -182,10 +169,12 @@ static bool supported_protocol(int idx)
 		idx <= server_conf.max_protocol);
 }
 
-static char *next_dialect(char *dialect, int *next_off)
+static char *next_dialect(char *dialect, int *next_off, int bcount)
 {
 	dialect = dialect + *next_off;
-	*next_off = strlen(dialect);
+	*next_off = strnlen(dialect, bcount);
+	if (dialect[*next_off] != '\0')
+		return NULL;
 	return dialect;
 }
 
@@ -200,7 +189,9 @@ static int ksmbd_lookup_dialect_by_name(char *cli_dialects, __le16 byte_count)
 		dialect = cli_dialects;
 		bcount = le16_to_cpu(byte_count);
 		do {
-			dialect = next_dialect(dialect, &next);
+			dialect = next_dialect(dialect, &next, bcount);
+			if (!dialect)
+				break;
 			ksmbd_debug(SMB, "client requested dialect %s\n",
 				    dialect);
 			if (!strcmp(dialect, smb1_protos[i].name)) {
@@ -248,13 +239,22 @@ int ksmbd_lookup_dialect_by_id(__le16 *cli_dialects, __le16 dialects_count)
 
 static int ksmbd_negotiate_smb_dialect(void *buf)
 {
-	__le32 proto;
+	int smb_buf_length = get_rfc1002_len(buf);
+	__le32 proto = ((struct smb2_hdr *)buf)->ProtocolId;
 
-	proto = ((struct smb2_hdr *)buf)->ProtocolId;
 	if (proto == SMB2_PROTO_NUMBER) {
 		struct smb2_negotiate_req *req;
+		int smb2_neg_size =
+			offsetof(struct smb2_negotiate_req, Dialects) - 4;
 
 		req = (struct smb2_negotiate_req *)buf;
+		if (smb2_neg_size > smb_buf_length)
+			goto err_out;
+
+		if (smb2_neg_size + le16_to_cpu(req->DialectCount) * sizeof(__le16) >
+		    smb_buf_length)
+			goto err_out;
+
 		return ksmbd_lookup_dialect_by_id(req->Dialects,
 						  req->DialectCount);
 	}
@@ -264,10 +264,19 @@ static int ksmbd_negotiate_smb_dialect(void *buf)
 		struct smb_negotiate_req *req;
 
 		req = (struct smb_negotiate_req *)buf;
+		if (le16_to_cpu(req->ByteCount) < 2)
+			goto err_out;
+
+		if (offsetof(struct smb_negotiate_req, DialectsArray) - 4 +
+			le16_to_cpu(req->ByteCount) > smb_buf_length) {
+			goto err_out;
+		}
+
 		return ksmbd_lookup_dialect_by_name(req->DialectsArray,
 						    req->ByteCount);
 	}
 
+err_out:
 	return BAD_PROT_ID;
 }
 

fs/ksmbd/smb_common.h

@@ -48,14 +48,6 @@
 #define CIFS_DEFAULT_IOSIZE	(64 * 1024)
 #define MAX_CIFS_SMALL_BUFFER_SIZE 448 /* big enough for most */
 
-/* RFC 1002 session packet types */
-#define RFC1002_SESSION_MESSAGE			0x00
-#define RFC1002_SESSION_REQUEST			0x81
-#define RFC1002_POSITIVE_SESSION_RESPONSE	0x82
-#define RFC1002_NEGATIVE_SESSION_RESPONSE	0x83
-#define RFC1002_RETARGET_SESSION_RESPONSE	0x84
-#define RFC1002_SESSION_KEEP_ALIVE		0x85
-
 /* Responses when opening a file. */
 #define F_SUPERSEDED	0
 #define F_OPENED	1

fs/ksmbd/smbacl.c

@@ -380,7 +380,7 @@ static void parse_dacl(struct user_namespace *user_ns,
 {
 	int i, ret;
 	int num_aces = 0;
-	int acl_size;
+	unsigned int acl_size;
 	char *acl_base;
 	struct smb_ace **ppace;
 	struct posix_acl_entry *cf_pace, *cf_pdace;
@@ -392,7 +392,7 @@ static void parse_dacl(struct user_namespace *user_ns,
 		return;
 
 	/* validate that we do not go past end of acl */
-	if (end_of_acl <= (char *)pdacl ||
+	if (end_of_acl < (char *)pdacl + sizeof(struct smb_acl) ||
 	    end_of_acl < (char *)pdacl + le16_to_cpu(pdacl->size)) {
 		pr_err("ACL too small to parse DACL\n");
 		return;
@@ -431,8 +431,22 @@ static void parse_dacl(struct user_namespace *user_ns,
 	 * user/group/other have no permissions
 	 */
 	for (i = 0; i < num_aces; ++i) {
+		if (end_of_acl - acl_base < acl_size)
+			break;
+
 		ppace[i] = (struct smb_ace *)(acl_base + acl_size);
 		acl_base = (char *)ppace[i];
+		acl_size = offsetof(struct smb_ace, sid) +
+			offsetof(struct smb_sid, sub_auth);
+
+		if (end_of_acl - acl_base < acl_size ||
+		    ppace[i]->sid.num_subauth > SID_MAX_SUB_AUTHORITIES ||
+		    (end_of_acl - acl_base <
+		     acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth) ||
+		    (le16_to_cpu(ppace[i]->size) <
+		     acl_size + sizeof(__le32) * ppace[i]->sid.num_subauth))
+			break;
+
 		acl_size = le16_to_cpu(ppace[i]->size);
 		ppace[i]->access_req =
 			smb_map_generic_desired_access(ppace[i]->access_req);
@@ -807,6 +821,9 @@ int parse_sec_desc(struct user_namespace *user_ns, struct smb_ntsd *pntsd,
 	if (!pntsd)
 		return -EIO;
 
+	if (acl_len < sizeof(struct smb_ntsd))
+		return -EINVAL;
+
 	owner_sid_ptr = (struct smb_sid *)((char *)pntsd +
 			le32_to_cpu(pntsd->osidoffset));
 	group_sid_ptr = (struct smb_sid *)((char *)pntsd +

fs/ksmbd/transport_tcp.c

@@ -215,7 +215,7 @@ static int ksmbd_tcp_new_connection(struct socket *client_sk)
  * ksmbd_kthread_fn() - listen to new SMB connections and callback server
  * @p:		arguments to forker thread
  *
- * Return:	Returns a task_struct or ERR_PTR
+ * Return:	0 on success, error number otherwise
  */
 static int ksmbd_kthread_fn(void *p)
 {
@@ -387,7 +387,7 @@ static void tcp_destroy_socket(struct socket *ksmbd_socket)
 /**
  * create_socket - create socket for ksmbd/0
  *
- * Return:	Returns a task_struct or ERR_PTR
+ * Return:	0 on success, error number otherwise
  */
 static int create_socket(struct interface *iface)
 {