Add additional safety check against invalid backup label file

petere · petere · commit e684ab5e1ec9 · 2012-03-14T22:41:50.000+02:00
It was already checking for invalid data after "BACKUP FROM", but
would possibly crash if "BACKUP FROM" was missing altogether.

found by Coverity
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
@@ -9481,7 +9481,7 @@ do_pg_stop_backup(char *labelfile, bool waitforarchive)
 	 * during the backup.
 	 */
 	ptr = strstr(remaining, "BACKUP FROM:");
-	if (sscanf(ptr, "BACKUP FROM: %19s\n", backupfrom) != 1)
+	if (!ptr || sscanf(ptr, "BACKUP FROM: %19s\n", backupfrom) != 1)
 		ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
 				 errmsg("invalid data in file \"%s\"", BACKUP_LABEL_FILE)));
