Fixes for bugs reported by Stefano Di Paola (stefano.dipaola@wisec.it)

include/my_global.h:
  O_NOFOLLOW
isam/create.c:
  create table files with O_EXCL|O_NOFOLLOW
merge/mrg_create.c:
  create table files with O_EXCL|O_NOFOLLOW
myisam/mi_create.c:
  create files of temporary tables with O_EXCL|O_NOFOLLOW
myisammrg/myrg_create.c:
  create table files with O_EXCL|O_NOFOLLOW
mysys/mf_tempfile.c:
  create temporary files with O_EXCL|O_NOFOLLOW
sql/ha_myisam.cc:
  let mi_create know if the table is TEMPORARY
sql/mysql_priv.h:
  --allow_suspicious_udfs
sql/mysqld.cc:
  --allow_suspicious_udfs
sql/share/english/errmsg.txt:
  typo
sql/sql_udf.cc:
  --allow_suspicious_udfs
  don't allow xxx() udf without any of xxx_init/deinit/add/reset
  check paths when loading from mysql.func
sql/table.cc:
  create frm of temporary table with O_EXCL|O_NOFOLLOW

include/my_global.h

@@ -500,6 +500,9 @@ typedef SOCKET_SIZE_TYPE size_socket;
 #ifndef O_SHORT_LIVED
 #define O_SHORT_LIVED	0
 #endif
+#ifndef O_NOFOLLOW
+#define O_NOFOLLOW      0
+#endif
 
 /* #define USE_RECORD_LOCK	*/
 

isam/create.c

@@ -58,13 +58,14 @@ int nisam_create(const char *name,uint keys,N_KEYDEF *keyinfo,
   base_pos=512;					/* Enough for N_STATE_INFO */
   bzero((byte*) &share,sizeof(share));
   if ((file = my_create(fn_format(buff,name,"",N_NAME_IEXT,4),0,
-       O_RDWR | O_TRUNC,MYF(MY_WME))) < 0)
+       O_RDWR | O_EXCL | O_NOFOLLOW,MYF(MY_WME))) < 0)
     goto err;
   errpos=1;
   VOID(fn_format(buff,name,"",N_NAME_DEXT,2+4));
   if (!(flags & HA_DONT_TOUCH_DATA))
   {
-    if ((dfile = my_create(buff,0,O_RDWR | O_TRUNC,MYF(MY_WME))) < 0)
+    if ((dfile = my_create(buff,0,O_RDWR | O_EXCL | O_NOFOLLOW,
+                           MYF(MY_WME))) < 0)
       goto err;
     errpos=2;
   }

merge/mrg_create.c

@@ -33,7 +33,7 @@ int mrg_create(const char *name, const char**table_names)
 
   errpos=0;
   if ((file = my_create(fn_format(buff,name,"",MRG_NAME_EXT,4),0,
-       O_RDWR | O_TRUNC,MYF(MY_WME))) < 0)
+       O_RDWR | O_EXCL | O_NOFOLLOW,MYF(MY_WME))) < 0)
     goto err;
   errpos=1;
   if (table_names)

myisam/mi_create.c

@@ -37,7 +37,7 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
 {
   register uint i,j;
   File dfile,file;
-  int errpos,save_errno;
+  int errpos,save_errno, create_mode= O_RDWR | O_TRUNC;
   myf create_flag;
   uint fields,length,max_key_length,packed,pointer,
        key_length,info_length,key_segs,options,min_key_length_skipp,
@@ -174,7 +174,10 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
     min_pack_length+=varchar_length+2*varchar_count;
   }
   if (flags & HA_CREATE_TMP_TABLE)
+  {
     options|= HA_OPTION_TMP_TABLE;
+    create_mode|= O_EXCL | O_NOFOLLOW;
+  }
   if (flags & HA_CREATE_CHECKSUM || (options & HA_OPTION_CHECKSUM))
   {
     options|= HA_OPTION_CHECKSUM;
@@ -508,9 +511,7 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
     create_flag=MY_DELETE_OLD;
   }
 
-  if ((file= my_create_with_symlink(linkname_ptr,
-				    filename,
-				    0, O_RDWR | O_TRUNC,
+  if ((file= my_create_with_symlink(linkname_ptr, filename, 0, create_mode,
 				    MYF(MY_WME | create_flag))) < 0)
     goto err;
   errpos=1;
@@ -521,7 +522,7 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
     if (share.base.raid_type)
     {
       (void) fn_format(filename,name,"",MI_NAME_DEXT,2+4);
-      if ((dfile=my_raid_create(filename,0,O_RDWR | O_TRUNC,
+      if ((dfile=my_raid_create(filename, 0, create_mode
 				share.base.raid_type,
 				share.base.raid_chunks,
 				share.base.raid_chunksize,
@@ -544,9 +545,8 @@ int mi_create(const char *name,uint keys,MI_KEYDEF *keydefs,
 	linkname_ptr=0;
 	create_flag=MY_DELETE_OLD;
       }
-      if ((dfile= 
-	   my_create_with_symlink(linkname_ptr, filename,
-				  0,O_RDWR | O_TRUNC,
+      if ((dfile=
+	   my_create_with_symlink(linkname_ptr, filename, 0, create_mode,
 				  MYF(MY_WME | create_flag))) < 0)
 	goto err;
     }

myisammrg/myrg_create.c

@@ -34,7 +34,7 @@ int myrg_create(const char *name, const char **table_names,
 
   errpos=0;
   if ((file = my_create(fn_format(buff,name,"",MYRG_NAME_EXT,4),0,
-       O_RDWR | O_TRUNC,MYF(MY_WME))) < 0)
+       O_RDWR | O_EXCL | O_NOFOLLOW,MYF(MY_WME))) < 0)
     goto err;
   errpos=1;
   if (table_names)

mysys/mf_tempfile.c

@@ -70,7 +70,7 @@ File create_temp_file(char *to, const char *dir, const char *prefix,
     {
       strmake(to,res,FN_REFLEN-1);
       (*free)(res);
-      file=my_create(to,0, mode, MyFlags);
+      file=my_create(to,0, mode | O_EXCL | O_NOFOLLOW, MyFlags);
     }
     environ=old_env;
   }
@@ -81,7 +81,7 @@ File create_temp_file(char *to, const char *dir, const char *prefix,
   {
     strmake(to,res,FN_REFLEN-1);
     (*free)(res);
-    file=my_create(to, 0, mode, MyFlags);
+    file=my_create(to, 0, mode | O_EXCL | O_NOFOLLOW, MyFlags);
   }
 #elif defined(HAVE_MKSTEMP) && !defined(__NETWARE__)
   {
@@ -143,7 +143,7 @@ File create_temp_file(char *to, const char *dir, const char *prefix,
       strmake(to,res,FN_REFLEN-1);
       (*free)(res);
       file=my_create(to,0,
-		     (int) (O_RDWR | O_BINARY | O_TRUNC |
+		     (int) (O_RDWR | O_BINARY | O_TRUNC | O_EXCL | O_NOFOLLOW |
 			    O_TEMPORARY | O_SHORT_LIVED),
 		     MYF(MY_WME));
 
@@ -186,7 +186,7 @@ File create_temp_file(char *to, const char *dir, const char *prefix,
       }
       (void) strmov(end_pos,TMP_EXT);
       file=my_create(to,0,
-		     (int) (O_RDWR | O_BINARY | O_TRUNC |
+		     (int) (O_RDWR | O_BINARY | O_TRUNC | O_EXCL | O_NOFOLLOW |
 			    O_TEMPORARY | O_SHORT_LIVED),
 		     MYF(MY_WME));
     }

sql/ha_myisam.cc

@@ -1052,7 +1052,7 @@ int ha_myisam::create(const char *name, register TABLE *table_arg,
 		      HA_CREATE_INFO *info)
 {
   int error;
-  uint i,j,recpos,minpos,fieldpos,temp_length,length;
+  uint i,j,recpos,minpos,fieldpos,temp_length,length, create_flags;
   bool found_real_auto_increment=0;
   enum ha_base_keytype type;
   char buff[FN_REFLEN];
@@ -1224,17 +1224,21 @@ int ha_myisam::create(const char *name, register TABLE *table_arg,
   create_info.data_file_name= info->data_file_name;
   create_info.index_file_name=info->index_file_name;
 
+  if (info->options & HA_LEX_CREATE_TMP_TABLE)
+    create_flags|= HA_CREATE_TMP_TABLE;
+  if (options & HA_OPTION_PACK_RECORD)
+    create_flags|= HA_PACK_RECORD;
+  if (options & HA_OPTION_CHECKSUM)
+    create_flags|= HA_CREATE_CHECKSUM;
+  if (options & HA_OPTION_DELAY_KEY_WRITE)
+    create_flags|= HA_CREATE_DELAY_KEY_WRITE;
+
   /* TODO: Check that the following fn_format is really needed */
   error=mi_create(fn_format(buff,name,"","",2+4),
 		  table_arg->keys,keydef,
 		  (uint) (recinfo_pos-recinfo), recinfo,
 		  0, (MI_UNIQUEDEF*) 0,
-		  &create_info,
-		  (((options & HA_OPTION_PACK_RECORD) ? HA_PACK_RECORD : 0) |
-		   ((options & HA_OPTION_CHECKSUM) ? HA_CREATE_CHECKSUM : 0) |
-		   ((options & HA_OPTION_DELAY_KEY_WRITE) ?
-		    HA_CREATE_DELAY_KEY_WRITE : 0)));
-
+		  &create_info, create_flags);
 
   my_free((gptr) recinfo,MYF(0));
   DBUG_RETURN(error);

sql/mysql_priv.h

@@ -728,7 +728,7 @@ extern my_bool opt_sql_bin_update, opt_safe_user_create, opt_no_mix_types;
 extern my_bool opt_safe_show_db, opt_local_infile;
 extern my_bool opt_slave_compressed_protocol, use_temp_pool;
 extern my_bool opt_readonly, lower_case_file_system;
-extern my_bool opt_enable_named_pipe, opt_sync_frm;
+extern my_bool opt_enable_named_pipe, opt_sync_frm, opt_allow_suspicious_udfs;
 
 extern MYSQL_LOG mysql_log,mysql_update_log,mysql_slow_log,mysql_bin_log;
 extern FILE *bootstrap_file;

sql/mysqld.cc

@@ -302,7 +302,7 @@ static pthread_t select_thread;
 static my_bool opt_noacl=0, opt_bootstrap=0, opt_myisam_log=0;
 my_bool opt_safe_user_create = 0, opt_no_mix_types = 0;
 my_bool opt_show_slave_auth_info, opt_sql_bin_update = 0;
-my_bool opt_log_slave_updates= 0, opt_console= 0;
+my_bool opt_log_slave_updates= 0, opt_console= 0, opt_allow_suspicious_udfs;
 my_bool opt_readonly = 0, opt_sync_bdb_logs, opt_sync_frm;
 
 volatile bool  mqh_used = 0;
@@ -3525,7 +3525,7 @@ enum options_mysqld {
   OPT_BDB_MAX_LOCK,
   OPT_ERROR_LOG_FILE,
   OPT_DEFAULT_WEEK_FORMAT,
-  OPT_RANGE_ALLOC_BLOCK_SIZE,
+  OPT_RANGE_ALLOC_BLOCK_SIZE, OPT_ALLOW_SUSPICIOUS_UDFS,
   OPT_QUERY_ALLOC_BLOCK_SIZE, OPT_QUERY_PREALLOC_SIZE,
   OPT_TRANS_ALLOC_BLOCK_SIZE, OPT_TRANS_PREALLOC_SIZE,
   OPT_SYNC_FRM, OPT_BDB_NOSYNC
@@ -3538,6 +3538,13 @@ struct my_option my_long_options[] =
 {
   {"ansi", 'a', "Use ANSI SQL syntax instead of MySQL syntax", 0, 0, 0,
    GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0},
+  {"allow-suspicious-udfs", OPT_ALLOW_SUSPICIOUS_UDFS,
+   "Allows to use UDF's consisting of only one symbol xxx() "
+   "without corresponing xxx_init() or xxx_deinit(). That also means "
+   "that one can load any function from any library, for example exit() "
+   "from libc.so",
+   (gptr*) &opt_allow_suspicious_udfs, (gptr*) &opt_allow_suspicious_udfs,
+   0, GET_BOOL, NO_ARG, 0, 0, 0, 0, 0, 0},
   {"basedir", 'b',
    "Path to installation directory. All paths are usually resolved relative to this.",
    (gptr*) &mysql_home_ptr, (gptr*) &mysql_home_ptr, 0, GET_STR, REQUIRED_ARG,

sql/share/english/errmsg.txt

@@ -141,7 +141,7 @@
 "No paths allowed for shared library",
 "Function '%-.64s' already exist",
 "Can't open shared library '%-.64s' (errno: %d %-.64s)",
-"Can't find function '%-.64s' in library'",
+"Can't find function '%-.64s' in library",
 "Function '%-.64s' is not defined",
 "Host '%-.64s' is blocked because of many connection errors.  Unblock with 'mysqladmin flush-hosts'",
 "Host '%-.64s' is not allowed to connect to this MySQL server",

sql/sql_udf.cc

@@ -73,29 +73,49 @@ static HASH udf_hash;
 static pthread_mutex_t THR_LOCK_udf;
 
 
-static udf_func *add_udf(char *name, Item_result ret, char *dl,
-			 Item_udftype typ);
+static udf_func *add_udf(char *name, Item_result ret,
+                         char *dl, Item_udftype typ);
 static void del_udf(udf_func *udf);
 static void *find_udf_dl(const char *dl);
 
-
-static void init_syms(udf_func *tmp)
+static char *init_syms(udf_func *tmp, char *nm)
 {
-  char nm[MAX_FIELD_NAME+16],*end;
+  char *end;
+
+  if (!((tmp->func= dlsym(tmp->dlhandle, tmp->name))))
+    return tmp->name;
 
-  tmp->func = dlsym(tmp->dlhandle, tmp->name);
   end=strmov(nm,tmp->name);
-  (void) strmov(end,"_init");
-  tmp->func_init = dlsym(tmp->dlhandle, nm);
-  (void) strmov(end,"_deinit");
-  tmp->func_deinit = dlsym(tmp->dlhandle, nm);
+
   if (tmp->type == UDFTYPE_AGGREGATE)
   {
-    (void)strmov( end, "_reset" );
-    tmp->func_reset = dlsym( tmp->dlhandle, nm );
-    (void)strmov( end, "_add" );
-    tmp->func_add = dlsym( tmp->dlhandle, nm );
+    (void)strmov(end, "_reset");
+    if (!((tmp->func_reset= dlsym(tmp->dlhandle, nm))))
+      return nm;
+    (void)strmov(end, "_add");
+    if (!((tmp->func_add= dlsym(tmp->dlhandle, nm))))
+      return nm;
+  }
+
+  (void) strmov(end,"_deinit");
+  tmp->func_deinit= dlsym(tmp->dlhandle, nm);
+
+  (void) strmov(end,"_init");
+  tmp->func_init= dlsym(tmp->dlhandle, nm);
+
+  /*
+    to prefent loading "udf" from, e.g. libc.so
+    let's ensure that at least one auxiliary symbol is defined
+  */
+  if (!tmp->func_init && !tmp->func_deinit && tmp->type != UDFTYPE_AGGREGATE)
+  {
+    if (opt_allow_suspicious_udfs)
+      sql_print_error(ER(ER_CANT_FIND_DL_ENTRY), nm);
+    else
+      return nm;
   }
+
+  return 0;
 }
 
 extern "C" byte* get_hash_key(const byte *buff,uint *length,
@@ -107,7 +127,7 @@ extern "C" byte* get_hash_key(const byte *buff,uint *length,
 }
 
 /*
-** Read all predeclared functions from func@mysql and accept all that
+** Read all predeclared functions from mysql.func and accept all that
 ** can be used.
 */
 
@@ -149,7 +169,7 @@ void udf_init()
   if (open_and_lock_tables(new_thd, &tables))
   {
     DBUG_PRINT("error",("Can't open udf table"));
-    sql_print_error("Can't open the mysql/func table. Please run the mysql_install_db script to create it.");
+    sql_print_error("Can't open the mysql.func table. Please run the mysql_install_db script to create it.");
     goto end;
   }
 
@@ -165,10 +185,22 @@ void udf_init()
     if (table->fields >= 4)			// New func table
       udftype=(Item_udftype) table->field[3]->val_int();
 
+    /*
+      Ensure that the .dll doesn't have a path
+      This is done to ensure that only approved dll from the system
+      directories are used (to make this even remotely secure).
+    */
+    if (strchr(dl_name, '/') || strlen(name) > NAME_LEN)
+    {
+      sql_print_error("Invalid row in mysql.func table for function '%.64s'",
+                      name);
+      continue;
+    }
+
     if (!(tmp = add_udf(name,(Item_result) table->field[1]->val_int(),
 			dl_name, udftype)))
     {
-      sql_print_error("Can't alloc memory for udf function: name");
+      sql_print_error("Can't alloc memory for udf function: '%.64s'", name);
       continue;
     }
 
@@ -186,13 +218,15 @@ void udf_init()
       new_dl=1;
     }
     tmp->dlhandle = dl;
-    init_syms(tmp);
-    if (!tmp->func)
     {
-      sql_print_error(ER(ER_CANT_FIND_DL_ENTRY), name);
-      del_udf(tmp);
-      if (new_dl)
-	dlclose(dl);
+      char buf[MAX_FIELD_NAME+16], *missing;
+      if ((missing= init_syms(tmp, buf)))
+      {
+        sql_print_error(ER(ER_CANT_FIND_DL_ENTRY), missing);
+        del_udf(tmp);
+        if (new_dl)
+          dlclose(dl);
+      }
     }
   }
   if (error > 0)
@@ -234,7 +268,7 @@ void udf_free()
   {
     initialized= 0;
     pthread_mutex_destroy(&THR_LOCK_udf);
-  }    
+  }
   DBUG_VOID_RETURN;
 }
 
@@ -398,13 +432,15 @@ int mysql_create_function(THD *thd,udf_func *udf)
     new_dl=1;
   }
   udf->dlhandle=dl;
-  init_syms(udf);
-
-  if (udf->func == NULL)
   {
-    net_printf(&thd->net, ER_CANT_FIND_DL_ENTRY, udf->name);
-    goto err;
+    char buf[MAX_FIELD_NAME+16], *missing;
+    if ((missing= init_syms(udf, buf)))
+    {
+      net_printf(&thd->net, ER_CANT_FIND_DL_ENTRY, missing);
+      goto err;
+    }
   }
+
   udf->name=strdup_root(&mem,udf->name);
   udf->dl=strdup_root(&mem,udf->dl);
   if (!(u_d=add_udf(udf->name,udf->returns,udf->dl,udf->type)))
@@ -419,7 +455,7 @@ int mysql_create_function(THD *thd,udf_func *udf)
   u_d->func_reset=udf->func_reset;
   u_d->func_add=udf->func_add;
 
-  /* create entry in mysql/func table */
+  /* create entry in mysql.func table */
 
   bzero((char*) &tables,sizeof(tables));
   tables.db= (char*) "mysql";
@@ -439,7 +475,7 @@ int mysql_create_function(THD *thd,udf_func *udf)
   close_thread_tables(thd);
   if (error)
   {
-    net_printf(&thd->net, ER_ERROR_ON_WRITE, "func@mysql",error);
+    net_printf(&thd->net, ER_ERROR_ON_WRITE, "mysql.func",error);
     del_udf(u_d);
     goto err;
   }

sql/table.cc

@@ -1048,6 +1048,10 @@ File create_frm(register my_string name, uint reclength, uchar *fileinfo,
   uint key_length;
   ulong length;
   char fill[IO_SIZE];
+  int create_flags= O_RDWR | O_TRUNC;
+
+  if (create_info->options & HA_LEX_CREATE_TMP_TABLE)
+    create_flags|= O_EXCL | O_NOFOLLOW;
 
 #if SIZEOF_OFF_T > 4
   /* Fix this in MySQL 4.0;  The current limit is 4G rows (QQ) */
@@ -1062,7 +1066,7 @@ File create_frm(register my_string name, uint reclength, uchar *fileinfo,
   */
   set_if_smaller(create_info->raid_chunks, 255);
 
-  if ((file=my_create(name,CREATE_MODE,O_RDWR | O_TRUNC,MYF(MY_WME))) >= 0)
+  if ((file= my_create(name, CREATE_MODE, create_flags, MYF(MY_WME))) >= 0)
   {
     bzero((char*) fileinfo,64);
     fileinfo[0]=(uchar) 254; fileinfo[1]= 1; fileinfo[2]= FRM_VER+1; // Header