ksmbd: return unsupported error on smb1 mount

ksmbd disconnect connection when mounting with vers=smb1.
ksmbd should send smb1 negotiate response to client for correct
unsupported error return. This patch add needed SMB1 macros and fill
NegProt part of the response for smb1 negotiate response.

Cc: stable@vger.kernel.org
Reported-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/ksmbd/connection.c b/fs/ksmbd/connection.c
index 5d914715605fbbb6190375d077f9c8b9053dad13..115a67d2cf7850f83a6102f52d35f76e0014ed47 100644 (file)
--- a/fs/ksmbd/connection.c
+++ b/fs/ksmbd/connection.c
@@ -319,13 +319,10 @@ int ksmbd_conn_handler_loop(void *p)
                }
 
                /*
-                * Check if pdu size is valid (min : smb header size,
-                * max : 0x00FFFFFF).
+                * Check maximum pdu size(0x00FFFFFF).
                 */
-               if (pdu_size < __SMB2_HEADER_STRUCTURE_SIZE ||
-                   pdu_size > MAX_STREAM_PROT_LEN) {
+               if (pdu_size > MAX_STREAM_PROT_LEN)
                        break;
-               }
 
                /* 4 for rfc1002 length field */
                size = pdu_size + 4;

diff --git a/fs/ksmbd/smb_common.c b/fs/ksmbd/smb_common.c
index 079c9e76818d8065d074084c4ac0a68f4fac2f0e..9c1ce6d199ce4a46ca9129f69d4715496779450c 100644 (file)
--- a/fs/ksmbd/smb_common.c
+++ b/fs/ksmbd/smb_common.c
@@ -442,9 +442,26 @@ static int smb_handle_negotiate(struct ksmbd_work *work)
 {
        struct smb_negotiate_rsp *neg_rsp = work->response_buf;
 
-       ksmbd_debug(SMB, "Unsupported SMB protocol\n");
-       neg_rsp->hdr.Status.CifsError = STATUS_INVALID_LOGON_TYPE;
-       return -EINVAL;
+       ksmbd_debug(SMB, "Unsupported SMB1 protocol\n");
+
+       /*
+        * Remove 4 byte direct TCP header, add 2 byte bcc and
+        * 2 byte DialectIndex.
+        */
+       *(__be32 *)work->response_buf =
+               cpu_to_be32(sizeof(struct smb_hdr) - 4 + 2 + 2);
+       neg_rsp->hdr.Status.CifsError = STATUS_SUCCESS;
+
+       neg_rsp->hdr.Command = SMB_COM_NEGOTIATE;
+       *(__le32 *)neg_rsp->hdr.Protocol = SMB1_PROTO_NUMBER;
+       neg_rsp->hdr.Flags = SMBFLG_RESPONSE;
+       neg_rsp->hdr.Flags2 = SMBFLG2_UNICODE | SMBFLG2_ERR_STATUS |
+               SMBFLG2_EXT_SEC | SMBFLG2_IS_LONG_NAME;
+
+       neg_rsp->hdr.WordCount = 1;
+       neg_rsp->DialectIndex = cpu_to_le16(work->conn->dialect);
+       neg_rsp->ByteCount = 0;
+       return 0;
 }
 
 int ksmbd_smb_negotiate_common(struct ksmbd_work *work, unsigned int command)

diff --git a/fs/ksmbd/smb_common.h b/fs/ksmbd/smb_common.h
index e663ab9ea759092d9e1cb0282b76d0059490581c..d30ce4c1a151703d9f4f512882ee5995a8f93773 100644 (file)
--- a/fs/ksmbd/smb_common.h
+++ b/fs/ksmbd/smb_common.h
@@ -158,8 +158,15 @@
 
 #define SMB1_PROTO_NUMBER              cpu_to_le32(0x424d53ff)
 #define SMB_COM_NEGOTIATE              0x72
-
 #define SMB1_CLIENT_GUID_SIZE          (16)
+
+#define SMBFLG_RESPONSE 0x80   /* this PDU is a response from server */
+
+#define SMBFLG2_IS_LONG_NAME   cpu_to_le16(0x40)
+#define SMBFLG2_EXT_SEC                cpu_to_le16(0x800)
+#define SMBFLG2_ERR_STATUS     cpu_to_le16(0x4000)
+#define SMBFLG2_UNICODE                cpu_to_le16(0x8000)
+
 struct smb_hdr {
        __be32 smb_buf_length;
        __u8 Protocol[4];
@@ -199,28 +206,7 @@ struct smb_negotiate_req {
 struct smb_negotiate_rsp {
        struct smb_hdr hdr;     /* wct = 17 */
        __le16 DialectIndex; /* 0xFFFF = no dialect acceptable */
-       __u8 SecurityMode;
-       __le16 MaxMpxCount;
-       __le16 MaxNumberVcs;
-       __le32 MaxBufferSize;
-       __le32 MaxRawSize;
-       __le32 SessionKey;
-       __le32 Capabilities;    /* see below */
-       __le32 SystemTimeLow;
-       __le32 SystemTimeHigh;
-       __le16 ServerTimeZone;
-       __u8 EncryptionKeyLength;
        __le16 ByteCount;
-       union {
-               unsigned char EncryptionKey[8]; /* cap extended security off */
-               /* followed by Domain name - if extended security is off */
-               /* followed by 16 bytes of server GUID */
-               /* then security blob if cap_extended_security negotiated */
-               struct {
-                       unsigned char GUID[SMB1_CLIENT_GUID_SIZE];
-                       unsigned char SecurityBlob[1];
-               } __packed extended_response;
-       } __packed u;
 } __packed;
 
 struct filesystem_attribute_info {