erts: Fix bug in enif_binary_to_term for immediates

Symptom: Heap corruption

Expanded test case to provoke this bug
and test some more term types.

2 files changed, 19 insertions, 8 deletions

diff --git a/erts/emulator/test/nif_SUITE.erl b/erts/emulator/test/nif_SUITE.erl
index 9c1694fa8a..4c5109c4ac 100644
--- a/erts/emulator/test/nif_SUITE.erl
+++ b/erts/emulator/test/nif_SUITE.erl
@@ -2111,16 +2111,23 @@ nif_term_to_binary(Config) ->
 
 nif_binary_to_term(Config) ->
     ensure_lib_loaded(Config),
-    T = {#{ok => nok}, <<0:8096>>, lists:seq(1,100)},
+    BigMap = maps:from_list([{I,-I} || I <- lists:seq(1,100)]),
+    [nif_binary_to_term_do(T)
+     || T <- [{#{ok => nok}, <<0:8096>>, lists:seq(1,100)},
+              atom, 42, self(), BigMap]],
+    ok.
+
+nif_binary_to_term_do(T) ->
+    Dummy = [true|false],
     Bin = term_to_binary(T),
     Len = byte_size(Bin),
-    {Len,T} = binary_to_term_nif(Bin, undefined, 0),
+    {Len,T,Dummy} = binary_to_term_nif(Bin, undefined, 0),
     Len = binary_to_term_nif(Bin, self(), 0),
-    T = receive M -> M after 1000 -> timeout end,
+    {T,Dummy} = receive M -> M after 1000 -> timeout end,
 
-    {Len, T} = binary_to_term_nif(Bin, undefined, ?ERL_NIF_BIN2TERM_SAFE),
+    {Len,T,Dummy} = binary_to_term_nif(Bin, undefined, ?ERL_NIF_BIN2TERM_SAFE),
     false = binary_to_term_nif(<<131,100,0,14,"undefined_atom">>,
-			   undefined, ?ERL_NIF_BIN2TERM_SAFE),
+                               undefined, ?ERL_NIF_BIN2TERM_SAFE),
     false = binary_to_term_nif(Bin, undefined, 1),
     ok.
 
diff --git a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
index f2b1ef9d24..3d262913aa 100644
--- a/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
+++ b/erts/emulator/test/nif_SUITE_data/nif_SUITE.c
@@ -1958,7 +1958,7 @@ static ERL_NIF_TERM term_to_binary(ErlNifEnv* env, int argc, const ERL_NIF_TERM
 static ERL_NIF_TERM binary_to_term(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
 {
     ErlNifBinary bin;
-    ERL_NIF_TERM term, ret_term;
+    ERL_NIF_TERM term, dummy, ret_term;
     ErlNifPid pid;
     ErlNifEnv *msg_env = env;
     unsigned int opts;
@@ -1971,6 +1971,9 @@ static ERL_NIF_TERM binary_to_term(ErlNifEnv* env, int argc, const ERL_NIF_TERM
 	|| !enif_get_uint(env, argv[2], &opts))
         return enif_make_badarg(env);
 
+    /* build dummy heap term first to provoke OTP-15080 */
+    dummy = enif_make_list_cell(msg_env, atom_true, atom_false);
+
     ret = enif_binary_to_term(msg_env, bin.data, bin.size, &term,
 			      (ErlNifBinaryToTerm)opts);
     if (!ret)
@@ -1978,11 +1981,12 @@ static ERL_NIF_TERM binary_to_term(ErlNifEnv* env, int argc, const ERL_NIF_TERM
 
     ret_term = enif_make_uint64(env, ret);
     if (msg_env != env) {
-        enif_send(env, &pid, msg_env, term);
+        enif_send(env, &pid, msg_env,
+                  enif_make_tuple2(msg_env, term, dummy));
         enif_free_env(msg_env);
         return ret_term;
     } else {
-        return enif_make_tuple2(env, ret_term, term);
+        return enif_make_tuple3(env, ret_term, term, dummy);
     }
 }