From 54ac9157e121175615485f89dbf90fc645435d17 Mon Sep 17 00:00:00 2001
From: Sverker Eriksson <sverker@erlang.org>
Date: Thu, 15 Feb 2018 13:44:19 +0100
Subject: kernel: Reject load of module names with slash

or backslash on Windows.

Purpose: Prevent tricks to get hostile code running.
---
 lib/kernel/src/code_server.erl | 27 +++++++++++++++++----------
 lib/kernel/src/kernel.app.src  |  2 +-
 2 files changed, 18 insertions(+), 11 deletions(-)

(limited to 'lib/kernel/src')

diff --git a/lib/kernel/src/code_server.erl b/lib/kernel/src/code_server.erl
index 418b0c50e1..f5a890cb95 100644
--- a/lib/kernel/src/code_server.erl
+++ b/lib/kernel/src/code_server.erl
@@ -340,8 +340,7 @@ handle_call(all_loaded, _From, S) ->
     {reply,all_loaded(Db),S};
 
 handle_call({get_object_code,Mod}, _From, St) when is_atom(Mod) ->
-    Path = St#state.path,
-    case mod_to_bin(Path, Mod) of
+    case get_object_code(St, Mod) of
 	{_,Bin,FName} -> {reply,{Mod,Bin,FName},St};
 	Error -> {reply,Error,St}
     end;
@@ -1182,19 +1181,28 @@ load_file(Mod, From, St0) ->
 	     end,
     handle_pending_on_load(Action, Mod, From, St0).
 
-load_file_1(Mod, From, #state{path=Path}=St) ->
-    case mod_to_bin(Path, Mod) of
+load_file_1(Mod, From, St) ->
+    case get_object_code(St, Mod) of
 	error ->
 	    {reply,{error,nofile},St};
 	{Mod,Binary,File} ->
 	    try_load_module_1(File, Mod, Binary, From, St)
     end.
 
-mod_to_bin([Dir|Tail], Mod) ->
-    File = filename:append(Dir, atom_to_list(Mod) ++ objfile_extension()),
+get_object_code(#state{path=Path}, Mod) when is_atom(Mod) ->
+    ModStr = atom_to_list(Mod),
+    case erl_prim_loader:is_basename(ModStr) of
+        true ->
+            mod_to_bin(Path, Mod, ModStr ++ objfile_extension());
+        false ->
+            error
+    end.
+
+mod_to_bin([Dir|Tail], Mod, ModFile) ->
+    File = filename:append(Dir, ModFile),
     case erl_prim_loader:get_file(File) of
 	error -> 
-	    mod_to_bin(Tail, Mod);
+	    mod_to_bin(Tail, Mod, ModFile);
 	{ok,Bin,_} ->
 	    case filename:pathtype(File) of
 		absolute ->
@@ -1203,10 +1211,9 @@ mod_to_bin([Dir|Tail], Mod) ->
 		    {Mod,Bin,absname(File)}
 	    end
     end;
-mod_to_bin([], Mod) ->
+mod_to_bin([], Mod, ModFile) ->
     %% At last, try also erl_prim_loader's own method
-    File = to_list(Mod) ++ objfile_extension(),
-    case erl_prim_loader:get_file(File) of
+    case erl_prim_loader:get_file(ModFile) of
 	error -> 
 	    error;     % No more alternatives !
 	{ok,Bin,FName} ->
diff --git a/lib/kernel/src/kernel.app.src b/lib/kernel/src/kernel.app.src
index 2a88cc7e26..0eca6fef03 100644
--- a/lib/kernel/src/kernel.app.src
+++ b/lib/kernel/src/kernel.app.src
@@ -120,6 +120,6 @@
   {applications, []},
   {env, [{error_logger, tty}]},
   {mod, {kernel, []}},
-  {runtime_dependencies, ["erts-9.1", "stdlib-3.4", "sasl-3.0"]}
+  {runtime_dependencies, ["erts-9.3", "stdlib-3.4", "sasl-3.0"]}
  ]
 }.
-- 
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