Merge tag '4.21-smb3-small-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull smb3 fixes from Steve French:
 "Three fixes, one for stable, one adds the (most secure) SMB3.1.1
  dialect to default list requested"

* tag '4.21-smb3-small-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: add smb3.1.1 to default dialect list
  cifs: fix confusing warning message on reconnect
  smb3: fix large reads on encrypted connections

4 files changed, 32 insertions, 16 deletions

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 69b9d5606eba..f66529679ca2 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -483,7 +483,7 @@ cifs_reconnect(struct TCP_Server_Info *server)
                 cifs_sb = NULL;
         } else {
                 rc = reconn_setup_dfs_targets(cifs_sb, &tgt_list, &tgt_it);
-                if (rc) {
+                if (rc && (rc != -EOPNOTSUPP)) {
                         cifs_dbg(VFS, "%s: no target servers for DFS failover\n",
                                  __func__);
                 } else {
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 33100ef74d7f..cf7eb891804f 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -3472,8 +3472,10 @@ smb3_receive_transform(struct TCP_Server_Info *server,
         }
 
         /* TODO: add support for compounds containing READ. */
-        if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server))
+        if (pdu_length > CIFSMaxBufSize + MAX_HEADER_SIZE(server)) {
+                *num_mids = 1;
                 return receive_encrypted_read(server, &mids[0]);
+        }
 
         return receive_encrypted_standard(server, mids, bufs, num_mids);
 }
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 {