diff --git a/fs/cifs/CHANGES b/fs/cifs/CHANGES
index f9e4ad97a79e708fc27a9896ead78aee49ed396a..06e521a945c33494130c7f1ab637d5ecfbef234c 100644
--- a/fs/cifs/CHANGES
+++ b/fs/cifs/CHANGES
@@ -9,7 +9,10 @@ files (e.g. "cp -a") to Windows servers.  For mkdir and create honor setgid bit
 on parent directory when server supports Unix Extensions but not POSIX
 create. Update cifs.upcall version to handle new Kerberos sec flags
 (this requires update of cifs.upcall program from Samba).  Fix memory leak
-on dns_upcall (resolving DFS referralls).
+on dns_upcall (resolving DFS referralls).  Fix plain text password
+authentication (requires setting SecurityFlags to 0x30030 to enable
+lanman and plain text though).  Fix writes to be at correct offset when
+file is open with O_APPEND and file is on a directio (forcediretio) mount.
 
 Version 1.53
 ------------
diff --git a/fs/cifs/README b/fs/cifs/README
index 68b5c1169d9d7e3eff5a3aff67cfb60980fa2050..bd2343d4c6a638218d50c80a9091ef3dd8205a14 100644
--- a/fs/cifs/README
+++ b/fs/cifs/README
@@ -542,10 +542,20 @@ SecurityFlags		Flags which control security negotiation and
 			hashing mechanisms (as "must use") on the other hand 
 			does not make much sense. Default flags are 
 				0x07007 
-			(NTLM, NTLMv2 and packet signing allowed).  Maximum 
+			(NTLM, NTLMv2 and packet signing allowed).  The maximum 
 			allowable flags if you want to allow mounts to servers
 			using weaker password hashes is 0x37037 (lanman,
-			plaintext, ntlm, ntlmv2, signing allowed):
+			plaintext, ntlm, ntlmv2, signing allowed).  Some
+			SecurityFlags require the corresponding menuconfig
+			options to be enabled (lanman and plaintext require
+			CONFIG_CIFS_WEAK_PW_HASH for example).  Enabling
+			plaintext authentication currently requires also
+			enabling lanman authentication in the security flags
+			because the cifs module only supports sending
+			laintext passwords using the older lanman dialect
+			form of the session setup SMB.  (e.g. for authentication
+			using plain text passwords, set the SecurityFlags
+			to 0x30030):
  
 			may use packet signing 				0x00001
 			must use packet signing				0x01001
diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 83fd40dc1ef0ffc3d6f1136f6966b90155481e98..bd5f13d38450ba5872658b2bee53a3ca017eb812 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -294,6 +294,7 @@ void calc_lanman_hash(struct cifsSesInfo *ses, char *lnm_session_key)
 
 	if ((ses->server->secMode & SECMODE_PW_ENCRYPT) == 0)
 		if (extended_security & CIFSSEC_MAY_PLNTXT) {
+			memset(lnm_session_key, 0, CIFS_SESS_KEY_SIZE);
 			memcpy(lnm_session_key, password_with_pad,
 				CIFS_ENCPWD_SIZE);
 			return;
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index ff14d14903a0c182667d757eadc390f3a509cc93..cbefe1f1f9fe2c4c92e97e8b4999039ba5c15b99 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -833,6 +833,10 @@ ssize_t cifs_user_write(struct file *file, const char __user *write_data,
 		return -EBADF;
 	open_file = (struct cifsFileInfo *) file->private_data;
 
+	rc = generic_write_checks(file, poffset, &write_size, 0);
+	if (rc)
+		return rc;
+
 	xid = GetXid();
 
 	if (*poffset > file->f_path.dentry->d_inode->i_size)
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index b537fad3bf50684c2b3405df74a69ea9dd9e29a3..252fdc0567f1aa186f36f8c68d83f259d6db4ee0 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -409,6 +409,8 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses, int first_time,
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 		char lnm_session_key[CIFS_SESS_KEY_SIZE];
 
+		pSMB->req.hdr.Flags2 &= ~SMBFLG2_UNICODE;
+
 		/* no capabilities flags in old lanman negotiation */
 
 		pSMB->old_req.PasswordLength = cpu_to_le16(CIFS_SESS_KEY_SIZE);