Merge tag '4.17-rc2-smb3' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
 "A few security related fixes for SMB3, most importantly for SMB3.11
  encryption"

* tag '4.17-rc2-smb3' of git://git.samba.org/sfrench/cifs-2.6:
  cifs: smbd: Avoid allocating iov on the stack
  cifs: smbd: Don't use RDMA read/write when signing is used
  SMB311: Fix reconnect
  SMB3: Fix 3.11 encryption to Windows and handle encrypted smb3 tcon
  CIFS: set *resp_buf_type to NO_BUFFER on error

7 files changed, 59 insertions, 54 deletions

diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index 6d3e40d7029c..1529a088383d 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -455,6 +455,9 @@ cifs_enable_signing(struct TCP_Server_Info *server, bool mnt_sign_required)
                 server->sign = true;
         }
 
+        if (cifs_rdma_enabled(server) && server->sign)
+                cifs_dbg(VFS, "Signing is enabled, and RDMA read/write will be disabled");
+
         return 0;
 }
 
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index e8830f076a7f..a5aa158d535a 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -2959,6 +2959,22 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
                 }
         }
 
+        if (volume_info->seal) {
+                if (ses->server->vals->protocol_id == 0) {
+                        cifs_dbg(VFS,
+                                 "SMB3 or later required for encryption\n");
+                        rc = -EOPNOTSUPP;
+                        goto out_fail;
+                } else if (tcon->ses->server->capabilities &
+                                        SMB2_GLOBAL_CAP_ENCRYPTION)
+                        tcon->seal = true;
+                else {
+                        cifs_dbg(VFS, "Encryption is not supported on share\n");
+                        rc = -EOPNOTSUPP;
+                        goto out_fail;
+                }
+        }
+
         /*
          * BB Do we need to wrap session_mutex around this TCon call and Unix
          * SetFS as we do on SessSetup and reconnect?
@@ -3007,22 +3023,6 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb_vol *volume_info)
                 tcon->use_resilient = true;
         }
 
-        if (volume_info->seal) {
-                if (ses->server->vals->protocol_id == 0) {
-                        cifs_dbg(VFS,
-                                 "SMB3 or later required for encryption\n");
-                        rc = -EOPNOTSUPP;
-                        goto out_fail;
-                } else if (tcon->ses->server->capabilities &
-                                        SMB2_GLOBAL_CAP_ENCRYPTION)
-                        tcon->seal = true;
-                else {
-                        cifs_dbg(VFS, "Encryption is not supported on share\n");
-                        rc = -EOPNOTSUPP;
-                        goto out_fail;
-                }
-        }
-
         /*
          * We can have only one retry value for a connection to a share so for
          * resources mounted more than once to the same server share the last
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 38ebf3f357d2..b76b85881dcc 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -252,9 +252,14 @@ smb2_negotiate_wsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
         wsize = volume_info->wsize ? volume_info->wsize : CIFS_DEFAULT_IOSIZE;
         wsize = min_t(unsigned int, wsize, server->max_write);
 #ifdef CONFIG_CIFS_SMB_DIRECT
-        if (server->rdma)
-                wsize = min_t(unsigned int,
+        if (server->rdma) {
+                if (server->sign)
+                        wsize = min_t(unsigned int,
+                                wsize, server->smbd_conn->max_fragmented_send_size);
+                else
+                        wsize = min_t(unsigned int,
                                 wsize, server->smbd_conn->max_readwrite_size);
+        }
 #endif
         if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
                 wsize = min_t(unsigned int, wsize, SMB2_MAX_BUFFER_SIZE);
@@ -272,9 +277,14 @@ smb2_negotiate_rsize(struct cifs_tcon *tcon, struct smb_vol *volume_info)
         rsize = volume_info->rsize ? volume_info->rsize : CIFS_DEFAULT_IOSIZE;
         rsize = min_t(unsigned int, rsize, server->max_read);
 #ifdef CONFIG_CIFS_SMB_DIRECT
-        if (server->rdma)
-                rsize = min_t(unsigned int,
+        if (server->rdma) {
+                if (server->sign)
+                        rsize = min_t(unsigned int,
+                                rsize, server->smbd_conn->max_fragmented_recv_size);
+                else
+                        rsize = min_t(unsigned int,
                                 rsize, server->smbd_conn->max_readwrite_size);
+        }
 #endif
 
         if (!(server->capabilities & SMB2_GLOBAL_CAP_LARGE_MTU))
diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index 0f044c4a2dc9..60db51bae0e3 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -383,10 +383,10 @@ static void
 build_encrypt_ctxt(struct smb2_encryption_neg_context *pneg_ctxt)
 {
         pneg_ctxt->ContextType = SMB2_ENCRYPTION_CAPABILITIES;
-        pneg_ctxt->DataLength = cpu_to_le16(6);
-        pneg_ctxt->CipherCount = cpu_to_le16(2);
-        pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM;
-        pneg_ctxt->Ciphers[1] = SMB2_ENCRYPTION_AES128_CCM;
+        pneg_ctxt->DataLength = cpu_to_le16(4); /* Cipher Count + le16 cipher */
+        pneg_ctxt->CipherCount = cpu_to_le16(1);
+/* pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_GCM;*/ /* not supported yet */
+        pneg_ctxt->Ciphers[0] = SMB2_ENCRYPTION_AES128_CCM;
 }
 
 static void
@@ -444,6 +444,7 @@ static int decode_encrypt_ctx(struct TCP_Server_Info *server,
                 return -EINVAL;
         }
         server->cipher_type = ctxt->Ciphers[0];
+        server->capabilities |= SMB2_GLOBAL_CAP_ENCRYPTION;
         return 0;
 }
 
@@ -2590,7 +2591,7 @@ smb2_new_read_req(void **buf, unsigned int *total_len,
          * If we want to do a RDMA write, fill in and append
          * smbd_buffer_descriptor_v1 to the end of read request
          */
-        if (server->rdma && rdata &&
+        if (server->rdma && rdata && !server->sign &&
                 rdata->bytes >= server->smbd_conn->rdma_readwrite_threshold) {
 
                 struct smbd_buffer_descriptor_v1 *v1;
@@ -2968,7 +2969,7 @@ smb2_async_writev(struct cifs_writedata *wdata,
          * If we want to do a server RDMA read, fill in and append
          * smbd_buffer_descriptor_v1 to the end of write request
          */
-        if (server->rdma && wdata->bytes >=
+        if (server->rdma && !server->sign && wdata->bytes >=
                 server->smbd_conn->rdma_readwrite_threshold) {
 
                 struct smbd_buffer_descriptor_v1 *v1;
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index 6093e5142b2b..d28f358022c5 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -297,7 +297,7 @@ struct smb2_encryption_neg_context {
         __le16  DataLength;
         __le32  Reserved;
         __le16  CipherCount; /* AES-128-GCM and AES-128-CCM */
-        __le16  Ciphers[2]; /* Ciphers[0] since only one used now */
+        __le16  Ciphers[1]; /* Ciphers[0] since only one used now */
 } __packed;
 
 struct smb2_negotiate_rsp {
diff --git a/fs/cifs/smbdirect.c b/fs/cifs/smbdirect.c
index 87817ddcc096..c62f7c95683c 100644
--- a/fs/cifs/smbdirect.c
+++ b/fs/cifs/smbdirect.c
@@ -2086,7 +2086,7 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)
         int start, i, j;
         int max_iov_size =
                 info->max_send_size - sizeof(struct smbd_data_transfer);
-        struct kvec iov[SMBDIRECT_MAX_SGE];
+        struct kvec *iov;
         int rc;
 
         info->smbd_send_pending++;
@@ -2096,32 +2096,20 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)
         }
 
         /*
-         * This usually means a configuration error
-         * We use RDMA read/write for packet size > rdma_readwrite_threshold
-         * as long as it's properly configured we should never get into this
-         * situation
-         */
-        if (rqst->rq_nvec + rqst->rq_npages > SMBDIRECT_MAX_SGE) {
-                log_write(ERR, "maximum send segment %x exceeding %x\n",
-                         rqst->rq_nvec + rqst->rq_npages, SMBDIRECT_MAX_SGE);
-                rc = -EINVAL;
-                goto done;
-        }
-
-        /*
-         * Remove the RFC1002 length defined in MS-SMB2 section 2.1
-         * It is used only for TCP transport
+         * Skip the RFC1002 length defined in MS-SMB2 section 2.1
+         * It is used only for TCP transport in the iov[0]
          * In future we may want to add a transport layer under protocol
          * layer so this will only be issued to TCP transport
          */
-        iov[0].iov_base = (char *)rqst->rq_iov[0].iov_base + 4;
-        iov[0].iov_len = rqst->rq_iov[0].iov_len - 4;
-        buflen += iov[0].iov_len;
+
+        if (rqst->rq_iov[0].iov_len != 4) {
+                log_write(ERR, "expected the pdu length in 1st iov, but got %zu\n", rqst->rq_iov[0].iov_len);
+                return -EINVAL;
+        }
+        iov = &rqst->rq_iov[1];
 
         /* total up iov array first */
-        for (i = 1; i < rqst->rq_nvec; i++) {
-                iov[i].iov_base = rqst->rq_iov[i].iov_base;
-                iov[i].iov_len = rqst->rq_iov[i].iov_len;
+        for (i = 0; i < rqst->rq_nvec-1; i++) {
                 buflen += iov[i].iov_len;
         }
 
@@ -2198,14 +2186,14 @@ int smbd_send(struct smbd_connection *info, struct smb_rqst *rqst)
                                                 goto done;
                                 }
                                 i++;
-                                if (i == rqst->rq_nvec)
+                                if (i == rqst->rq_nvec-1)
                                         break;
                         }
                         start = i;
                         buflen = 0;
                 } else {
                         i++;
-                        if (i == rqst->rq_nvec) {
+                        if (i == rqst->rq_nvec-1) {
                                 /* send out all remaining vecs */
                                 remaining_data_length -= buflen;
                                 log_write(INFO,
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 8f6f25918229..927226a2122f 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -753,7 +753,7 @@ cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
                 goto out;
 
 #ifdef CONFIG_CIFS_SMB311
-        if (ses->status == CifsNew)
+        if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP))
                 smb311_update_preauth_hash(ses, rqst->rq_iov+1,
                                            rqst->rq_nvec-1);
 #endif
@@ -798,7 +798,7 @@ cifs_send_recv(const unsigned int xid, struct cifs_ses *ses,
                 *resp_buf_type = CIFS_SMALL_BUFFER;
 
 #ifdef CONFIG_CIFS_SMB311
-        if (ses->status == CifsNew) {
+        if ((ses->status == CifsNew) || (optype & CIFS_NEG_OP)) {
                 struct kvec iov = {
                         .iov_base = buf + 4,
                         .iov_len = get_rfc1002_length(buf)
@@ -834,8 +834,11 @@ SendReceive2(const unsigned int xid, struct cifs_ses *ses,
         if (n_vec + 1 > CIFS_MAX_IOV_SIZE) {
                 new_iov = kmalloc(sizeof(struct kvec) * (n_vec + 1),
                                   GFP_KERNEL);
-                if (!new_iov)
+                if (!new_iov) {
+                        /* otherwise cifs_send_recv below sets resp_buf_type */
+                        *resp_buf_type = CIFS_NO_BUFFER;
                         return -ENOMEM;
+                }
         } else
                 new_iov = s_iov;