[CIFS] clean up error handling in cifs_mount

Move all of the kfree's sprinkled in the middle of the function to the
end, and have the code set rc and just goto there on error. Also zero
out the password string before freeing it. Looks like this should also
fix a potential memory leak of the prepath string if an error occurs
near the end of the function.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 26e1087..58c509e 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1781,11 +1781,8 @@
 
 	memset(&volume_info, 0, sizeof(struct smb_vol));
 	if (cifs_parse_mount_options(mount_data, devname, &volume_info)) {
-		kfree(volume_info.UNC);
-		kfree(volume_info.password);
-		kfree(volume_info.prepath);
-		FreeXid(xid);
-		return -EINVAL;
+		rc = -EINVAL;
+		goto out;
 	}
 
 	if (volume_info.nullauth) {
@@ -1798,11 +1795,8 @@
 		cifserror("No username specified");
 	/* In userspace mount helper we can get user name from alternate
 	   locations such as env variables and files on disk */
-		kfree(volume_info.UNC);
-		kfree(volume_info.password);
-		kfree(volume_info.prepath);
-		FreeXid(xid);
-		return -EINVAL;
+		rc = -EINVAL;
+		goto out;
 	}
 
 	if (volume_info.UNCip && volume_info.UNC) {
@@ -1821,11 +1815,8 @@
 
 		if (rc <= 0) {
 			/* we failed translating address */
-			kfree(volume_info.UNC);
-			kfree(volume_info.password);
-			kfree(volume_info.prepath);
-			FreeXid(xid);
-			return -EINVAL;
+			rc = -EINVAL;
+			goto out;
 		}
 
 		cFYI(1, ("UNC: %s ip: %s", volume_info.UNC, volume_info.UNCip));
@@ -1835,20 +1826,14 @@
 		/* BB using ip addr as server name to connect to the
 		   DFS root below */
 		cERROR(1, ("Connecting to DFS root not implemented yet"));
-		kfree(volume_info.UNC);
-		kfree(volume_info.password);
-		kfree(volume_info.prepath);
-		FreeXid(xid);
-		return -EINVAL;
+		rc = -EINVAL;
+		goto out;
 	} else /* which servers DFS root would we conect to */ {
 		cERROR(1,
 		       ("CIFS mount error: No UNC path (e.g. -o "
 			"unc=//192.168.1.100/public) specified"));
-		kfree(volume_info.UNC);
-		kfree(volume_info.password);
-		kfree(volume_info.prepath);
-		FreeXid(xid);
-		return -EINVAL;
+		rc = -EINVAL;
+		goto out;
 	}
 
 	/* this is needed for ASCII cp to Unicode converts */
@@ -1860,11 +1845,8 @@
 		if (cifs_sb->local_nls == NULL) {
 			cERROR(1, ("CIFS mount error: iocharset %s not found",
 				 volume_info.iocharset));
-			kfree(volume_info.UNC);
-			kfree(volume_info.password);
-			kfree(volume_info.prepath);
-			FreeXid(xid);
-			return -ELIBACC;
+			rc = -ELIBACC;
+			goto out;
 		}
 	}
 
@@ -1878,11 +1860,8 @@
 			&sin_server6.sin6_addr,
 			volume_info.username, &srvTcp);
 	} else {
-		kfree(volume_info.UNC);
-		kfree(volume_info.password);
-		kfree(volume_info.prepath);
-		FreeXid(xid);
-		return -EINVAL;
+		rc = -EINVAL;
+		goto out;
 	}
 
 	if (srvTcp) {
@@ -1906,22 +1885,14 @@
 				   "Aborting operation"));
 			if (csocket != NULL)
 				sock_release(csocket);
-			kfree(volume_info.UNC);
-			kfree(volume_info.password);
-			kfree(volume_info.prepath);
-			FreeXid(xid);
-			return rc;
+			goto out;
 		}
 
 		srvTcp = kzalloc(sizeof(struct TCP_Server_Info), GFP_KERNEL);
 		if (!srvTcp) {
 			rc = -ENOMEM;
 			sock_release(csocket);
-			kfree(volume_info.UNC);
-			kfree(volume_info.password);
-			kfree(volume_info.prepath);
-			FreeXid(xid);
-			return rc;
+			goto out;
 		} else {
 			memcpy(&srvTcp->addr.sockAddr, &sin_server,
 				sizeof(struct sockaddr_in));
@@ -1943,11 +1914,7 @@
 				cERROR(1, ("error %d create cifsd thread", rc));
 				srvTcp->tsk = NULL;
 				sock_release(csocket);
-				kfree(volume_info.UNC);
-				kfree(volume_info.password);
-				kfree(volume_info.prepath);
-				FreeXid(xid);
-				return rc;
+				goto out;
 			}
 			wait_for_completion(&cifsd_complete);
 			rc = 0;
@@ -1962,8 +1929,6 @@
 	if (existingCifsSes) {
 		pSesInfo = existingCifsSes;
 		cFYI(1, ("Existing smb sess found"));
-		kfree(volume_info.password);
-		/* volume_info.UNC freed at end of function */
 	} else if (!rc) {
 		cFYI(1, ("Existing smb sess not found"));
 		pSesInfo = sesInfoAlloc();
@@ -1977,8 +1942,11 @@
 
 		if (!rc) {
 			/* volume_info.password freed at unmount */
-			if (volume_info.password)
+			if (volume_info.password) {
 				pSesInfo->password = volume_info.password;
+				/* set to NULL to prevent freeing on exit */
+				volume_info.password = NULL;
+			}
 			if (volume_info.username)
 				strncpy(pSesInfo->userName,
 					volume_info.username,
@@ -2000,8 +1968,7 @@
 			up(&pSesInfo->sesSem);
 			if (!rc)
 				atomic_inc(&srvTcp->socketUseCount);
-		} else
-			kfree(volume_info.password);
+		}
 	}
 
 	/* search for existing tcon to this server share */
@@ -2106,9 +2073,8 @@
 						"", cifs_sb->local_nls,
 						cifs_sb->mnt_cifs_flags &
 						  CIFS_MOUNT_MAP_SPECIAL_CHR);
-					kfree(volume_info.UNC);
-					FreeXid(xid);
-					return -ENODEV;
+					rc = -ENODEV;
+					goto out;
 				} else {
 					/* BB Do we need to wrap sesSem around
 					 * this TCon call and Unix SetFS as
@@ -2231,6 +2197,12 @@
 	(in which case it is not needed anymore) but when new sesion is created
 	the password ptr is put in the new session structure (in which case the
 	password will be freed at unmount time) */
+out:
+	/* zero out password before freeing */
+	if (volume_info.password != NULL) {
+		memset(volume_info.password, 0, strlen(volume_info.password));
+		kfree(volume_info.password);
+	}
 	kfree(volume_info.UNC);
 	kfree(volume_info.prepath);
 	FreeXid(xid);