enif_release_resource is not NULL safe

* Add if checks and update coccinelle script.

6 files changed, 45 insertions, 13 deletions

diff --git a/lib/crypto/c_src/aes.c b/lib/crypto/c_src/aes.c
index 94b874298e..205cb8b058 100644
--- a/lib/crypto/c_src/aes.c
+++ b/lib/crypto/c_src/aes.c
@@ -223,7 +223,8 @@ ERL_NIF_TERM aes_ctr_stream_init(ErlNifEnv* env, int argc, const ERL_NIF_TERM ar
     ret = enif_make_badarg(env);
 
  done:
-    enif_release_resource(ctx);
+    if (ctx)
+        enif_release_resource(ctx);
     return ret;
 }
 
@@ -270,7 +271,8 @@ ERL_NIF_TERM aes_ctr_stream_encrypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM
     ret = enif_make_badarg(env);
 
  done:
-    enif_release_resource(new_ctx);
+    if (new_ctx)
+        enif_release_resource(new_ctx);
     return ret;
 }
 
diff --git a/lib/crypto/c_src/chacha20.c b/lib/crypto/c_src/chacha20.c
index 03b8589524..51a24a43e9 100644
--- a/lib/crypto/c_src/chacha20.c
+++ b/lib/crypto/c_src/chacha20.c
@@ -63,7 +63,8 @@ ERL_NIF_TERM chacha20_stream_init(ErlNifEnv* env, int argc, const ERL_NIF_TERM a
     ret = enif_make_badarg(env);
 
  done:
-    enif_release_resource(ctx);
+    if (ctx)
+        enif_release_resource(ctx);
     return ret;
 
 #else
@@ -113,7 +114,8 @@ ERL_NIF_TERM chacha20_stream_crypt(ErlNifEnv* env, int argc, const ERL_NIF_TERM
     ret = enif_make_badarg(env);
 
  done:
-    enif_release_resource(new_ctx);
+    if (new_ctx)
+        enif_release_resource(new_ctx);
     return ret;
 
 #else
diff --git a/lib/crypto/c_src/check_erlang.cocci b/lib/crypto/c_src/check_erlang.cocci
index bdb99d5bb0..eba0e3935c 100644
--- a/lib/crypto/c_src/check_erlang.cocci
+++ b/lib/crypto/c_src/check_erlang.cocci
@@ -39,7 +39,8 @@ position p;
    goto L;
 
  ... when strict, forall
- enif_release_resource(CTX)
+ if (CTX)
+   enif_release_resource(CTX);
 
 
 // After calling enif_alloc_binary(), you must either release it with
@@ -93,7 +94,7 @@ position pa, pm, pr;
 // enif_has_pending_exception  returns true if exception pending
 
 @erlang_check_void@
-identifier FUNCVOID =~ "^(enif_free|enif_mutex_destroy|enif_mutex_lock|enif_mutex_unlock|enif_release_binary|enif_release_resource|enif_rwlock_destroy|enif_rwlock_rlock|enif_rwlock_runlock|enif_rwlock_rwlock|enif_rwlock_rwunlock|enif_system_info)$";
+identifier FUNCVOID =~ "^(enif_free|enif_mutex_destroy|enif_mutex_lock|enif_mutex_unlock|enif_release_binary|enif_rwlock_destroy|enif_rwlock_rlock|enif_rwlock_runlock|enif_rwlock_rwlock|enif_rwlock_rwunlock|enif_system_info)$";
 position p;
 @@
 
@@ -133,6 +134,22 @@ position p;
 )
 
 
+@erlang_check_null_free@
+expression X;
+identifier FUNCFREE =~ "^(enif_release_resource)$";
+position p;
+@@
+
+  if (
+(
+ X
+|
+ X != NULL
+)
+  )
+    FUNCFREE(X)@p;
+
+
 @erlang_check_new@
 expression RET;
 identifier FUNCNEW =~ "^(enif_make_atom|enif_make_badarg|enif_make_binary|enif_make_int|enif_make_list|enif_make_list_from_array|enif_make_resource|enif_make_tuple|enif_raise_exception|enif_schedule_nif|enif_thread_self)$";
@@ -149,7 +166,7 @@ position p;
 // Flag any calls that aren't part of the above pattern.
 @enif_alloc_not_free@
 
-identifier FUNCVOID =~ "^(enif_free|enif_mutex_destroy|enif_mutex_lock|enif_mutex_unlock|enif_release_binary|enif_release_resource|enif_rwlock_destroy|enif_rwlock_rlock|enif_rwlock_runlock|enif_rwlock_rwlock|enif_rwlock_rwunlock|enif_system_info)$";
+identifier FUNCVOID =~ "^(enif_free|enif_mutex_destroy|enif_mutex_lock|enif_mutex_unlock|enif_release_binary|enif_rwlock_destroy|enif_rwlock_rlock|enif_rwlock_runlock|enif_rwlock_rwlock|enif_rwlock_rwunlock|enif_system_info)$";
 position pvoid != {erlang_check_void.p,enif_alloc_binary.pr};
 
 identifier FUNCNULL =~ "^(enif_alloc|enif_alloc_resource|enif_dlopen|enif_dlsym|enif_make_new_binary|enif_mutex_create|enif_open_resource_type|enif_realloc|enif_rwlock_create)$";
@@ -161,6 +178,9 @@ position pnot != {erlang_check_not.p,enif_alloc_binary.pa};
 identifier FUNCNEW =~ "^(enif_make_atom|enif_make_badarg|enif_make_binary|enif_make_int|enif_make_list|enif_make_list_from_array|enif_make_resource|enif_make_tuple|enif_raise_exception|enif_schedule_nif|enif_thread_self)$";
 position pnew != {erlang_check_new.p,enif_alloc_binary.pm};
 
+identifier FUNCFREE =~ "^(enif_release_resource)$";
+position pfree != {enif_alloc_resource.p,erlang_check_null_free.p};
+
 @@
 
 (
@@ -171,4 +191,6 @@ position pnew != {erlang_check_new.p,enif_alloc_binary.pm};
 * FUNCNOT(...)@pnot
 |
 * FUNCNEW(...)@pnew
+|
+* FUNCFREE(...)@pfree
 )
diff --git a/lib/crypto/c_src/engine.c b/lib/crypto/c_src/engine.c
index 44648280b4..90fc8b66cd 100644
--- a/lib/crypto/c_src/engine.c
+++ b/lib/crypto/c_src/engine.c
@@ -158,7 +158,8 @@ ERL_NIF_TERM engine_by_id_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[
  done:
     if (engine_id)
         enif_free(engine_id);
-    enif_release_resource(ctx);
+    if (ctx)
+        enif_release_resource(ctx);
     return ret;
 
 #else
@@ -604,7 +605,8 @@ ERL_NIF_TERM engine_get_first_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM a
     ret = enif_make_badarg(env);
 
  done:
-    enif_release_resource(ctx);
+    if (ctx)
+        enif_release_resource(ctx);
     return ret;
 
 #else
@@ -647,7 +649,8 @@ ERL_NIF_TERM engine_get_next_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM ar
     ret = enif_make_badarg(env);
 
  done:
-    enif_release_resource(next_ctx);
+    if (next_ctx)
+        enif_release_resource(next_ctx);
     return ret;
 
 #else
diff --git a/lib/crypto/c_src/hash.c b/lib/crypto/c_src/hash.c
index a90957f1a7..000eae047a 100644
--- a/lib/crypto/c_src/hash.c
+++ b/lib/crypto/c_src/hash.c
@@ -130,7 +130,8 @@ ERL_NIF_TERM hash_init_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
     ret = atom_notsup;
 
  done:
-    enif_release_resource(ctx);
+    if (ctx)
+        enif_release_resource(ctx);
     return ret;
 }
 
@@ -167,7 +168,8 @@ ERL_NIF_TERM hash_update_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[]
     ret = atom_notsup;
 
  done:
-    enif_release_resource(new_ctx);
+    if (new_ctx)
+        enif_release_resource(new_ctx);
     return ret;
 }
 
diff --git a/lib/crypto/c_src/hmac.c b/lib/crypto/c_src/hmac.c
index a5ff35c706..9418e7950e 100644
--- a/lib/crypto/c_src/hmac.c
+++ b/lib/crypto/c_src/hmac.c
@@ -169,7 +169,8 @@ ERL_NIF_TERM hmac_init_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
     ret = atom_notsup;
 
  done:
-    enif_release_resource(obj);
+    if (obj)
+        enif_release_resource(obj);
     return ret;
 }