From: Steve French <stfrench@microsoft.com>
Date: Thu, 3 Jan 2019 02:37:21 -0600
Subject: [PATCH] smb3: add smb3.1.1 to default dialect list
Git-commit: d5c7076b772ad7dcdb92303397b36aee8fa0d25d
Patch-mainline: v5.0-rc1
References: bsc#1144333

SMB3.1.1 dialect has additional security (among other) features
and should be requested when mounting to modern servers so it
can be used if the server supports it.

Add SMB3.1.1 to the default list of dialects requested.

Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
---
 fs/cifs/smb2pdu.c | 40 +++++++++++++++++++++++++++-------------
 fs/cifs/smb2pdu.h |  2 +-
 2 files changed, 28 insertions(+), 14 deletions(-)

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index e283590955cd..e57f6aa1d638 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -451,10 +451,6 @@ smb2_plain_req_init(__le16 smb2_command, struct cifs_tcon *tcon,
 }
 
 
-/* offset is sizeof smb2_negotiate_req but rounded up to 8 bytes */
-#define OFFSET_OF_NEG_CONTEXT 0x68  /* sizeof(struct smb2_negotiate_req) */
-
-
 #define SMB2_PREAUTH_INTEGRITY_CAPABILITIES	cpu_to_le16(1)
 #define SMB2_ENCRYPTION_CAPABILITIES		cpu_to_le16(2)
 #define SMB2_POSIX_EXTENSIONS_AVAILABLE		cpu_to_le16(0x100)
@@ -491,10 +487,24 @@ static void
 assemble_neg_contexts(struct smb2_negotiate_req *req,
 		      unsigned int *total_len)
 {
-	char *pneg_ctxt = (char *)req + OFFSET_OF_NEG_CONTEXT;
+	char *pneg_ctxt = (char *)req;
 	unsigned int ctxt_len;
 
-	*total_len += 2; /* Add 2 due to round to 8 byte boundary for 1st ctxt */
+	if (*total_len > 200) {
+		/* In case length corrupted don't want to overrun smb buffer */
+		cifs_dbg(VFS, "Bad frame length assembling neg contexts\n");
+		return;
+	}
+
+	/*
+	 * round up total_len of fixed part of SMB3 negotiate request to 8
+	 * byte boundary before adding negotiate contexts
+	 */
+	*total_len = roundup(*total_len, 8);
+
+	pneg_ctxt = (*total_len) + (char *)req;
+	req->NegotiateContextOffset = cpu_to_le32(*total_len);
+
 	build_preauth_ctxt((struct smb2_preauth_neg_context *)pneg_ctxt);
 	ctxt_len = DIV_ROUND_UP(sizeof(struct smb2_preauth_neg_context), 8) * 8;
 	*total_len += ctxt_len;
@@ -508,7 +518,6 @@ assemble_neg_contexts(struct smb2_negotiate_req *req,
 	build_posix_ctxt((struct smb2_posix_neg_context *)pneg_ctxt);
 	*total_len += sizeof(struct smb2_posix_neg_context);
 
-	req->NegotiateContextOffset = cpu_to_le32(OFFSET_OF_NEG_CONTEXT);
 	req->NegotiateContextCount = cpu_to_le16(3);
 }
 
@@ -724,8 +733,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
 		req->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
 		req->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
 		req->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
-		req->DialectCount = cpu_to_le16(3);
-		total_len += 6;
+		req->Dialects[3] = cpu_to_le16(SMB311_PROT_ID);
+		req->DialectCount = cpu_to_le16(4);
+		total_len += 8;
 	} else {
 		/* otherwise send specific dialect */
 		req->Dialects[0] = cpu_to_le16(ses->server->vals->protocol_id);
@@ -749,7 +759,9 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
 	else {
 		memcpy(req->ClientGUID, server->client_guid,
 			SMB2_CLIENT_GUID_SIZE);
-		if (ses->server->vals->protocol_id == SMB311_PROT_ID)
+		if ((ses->server->vals->protocol_id == SMB311_PROT_ID) ||
+		    (strcmp(ses->server->vals->version_string,
+		     SMBDEFAULT_VERSION_STRING) == 0))
 			assemble_neg_contexts(req, &total_len);
 	}
 	iov[0].iov_base = (char *)req;
@@ -794,7 +806,8 @@ SMB2_negotiate(const unsigned int xid, struct cifs_ses *ses)
 		} else if (rsp->DialectRevision == cpu_to_le16(SMB21_PROT_ID)) {
 			/* ops set to 3.0 by default for default so update */
 			ses->server->ops = &smb21_operations;
-		}
+		} else if (rsp->DialectRevision == cpu_to_le16(SMB311_PROT_ID))
+			ses->server->ops = &smb311_operations;
 	} else if (le16_to_cpu(rsp->DialectRevision) !=
 				ses->server->vals->protocol_id) {
 		/* if requested single dialect ensure returned dialect matched */
@@ -941,13 +954,14 @@ int smb3_validate_negotiate(const unsigned int xid, struct cifs_tcon *tcon)
 		pneg_inbuf->DialectCount = cpu_to_le16(2);
 		/* structure is big enough for 3 dialects, sending only 2 */
 		inbuflen = sizeof(*pneg_inbuf) -
-				sizeof(pneg_inbuf->Dialects[0]);
+				(2 * sizeof(pneg_inbuf->Dialects[0]));
 	} else if (strcmp(tcon->ses->server->vals->version_string,
 		SMBDEFAULT_VERSION_STRING) == 0) {
 		pneg_inbuf->Dialects[0] = cpu_to_le16(SMB21_PROT_ID);
 		pneg_inbuf->Dialects[1] = cpu_to_le16(SMB30_PROT_ID);
 		pneg_inbuf->Dialects[2] = cpu_to_le16(SMB302_PROT_ID);
-		pneg_inbuf->DialectCount = cpu_to_le16(3);
+		pneg_inbuf->Dialects[3] = cpu_to_le16(SMB311_PROT_ID);
+		pneg_inbuf->DialectCount = cpu_to_le16(4);
 		/* structure is big enough for 3 dialects */
 		inbuflen = sizeof(*pneg_inbuf);
 	} else {
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 05dea6750c33..7a2d0a2255e6 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -898,7 +898,7 @@ struct validate_negotiate_info_req {
 	__u8   Guid[SMB2_CLIENT_GUID_SIZE];
 	__le16 SecurityMode;
 	__le16 DialectCount;
-	__le16 Dialects[3]; /* BB expand this if autonegotiate > 3 dialects */
+	__le16 Dialects[4]; /* BB expand this if autonegotiate > 4 dialects */
 } __packed;
 
 struct validate_negotiate_info_rsp {
-- 
2.16.4