From: Harald Anlauf <anlauf@gmx.de>
Date: Wed, 10 Nov 2021 19:30:27 +0000 (+0100)
Subject: Fortran: avoid NULL pointer dereferences
X-Git-Tag: basepoints/gcc-13~3177
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=abc2f01914d6c4703de26c402fb579a9a2d0dba4;p=thirdparty%2Fgcc.git

Fortran: avoid NULL pointer dereferences

CLASS(), PARAMETER is not yet properly implemented in gfortran.  Using it
in declarations could lead to subsequent NULL pointer dereferences during
checking or simplification of expressions involving those CLASS variables.

gcc/fortran/ChangeLog:

	PR fortran/103137
	PR fortran/103138
	* check.c (gfc_check_shape): Avoid NULL pointer dereference on
	missing ref.
	* simplify.c (gfc_simplify_cshift): Avoid NULL pointer dereference
	when shape not set.
	(gfc_simplify_transpose): Likewise.
---

diff --git a/gcc/fortran/check.c b/gcc/fortran/check.c
index 15772009af47..ffa07b510cd8 100644
--- a/gcc/fortran/check.c
+++ b/gcc/fortran/check.c
@@ -5096,6 +5096,9 @@ gfc_check_shape (gfc_expr *source, gfc_expr *kind)
   if (source->rank == 0 || source->expr_type != EXPR_VARIABLE)
     return true;
 
+  if (source->ref == NULL)
+    return false;
+
   ar = gfc_find_array_ref (source);
 
   if (ar->as && ar->as->type == AS_ASSUMED_SIZE && ar->type == AR_FULL)
diff --git a/gcc/fortran/simplify.c b/gcc/fortran/simplify.c
index d675f2c3aeff..6a6b3fbd0375 100644
--- a/gcc/fortran/simplify.c
+++ b/gcc/fortran/simplify.c
@@ -2109,6 +2109,9 @@ gfc_simplify_cshift (gfc_expr *array, gfc_expr *shift, gfc_expr *dim)
   else
     which = 0;
 
+  if (array->shape == NULL)
+    return NULL;
+
   gfc_array_size (array, &size);
   arraysize = mpz_get_ui (size);
   mpz_clear (size);
@@ -8174,6 +8177,9 @@ gfc_simplify_transpose (gfc_expr *matrix)
 
   gcc_assert (matrix->rank == 2);
 
+  if (matrix->shape == NULL)
+    return NULL;
+
   result = gfc_get_array_expr (matrix->ts.type, matrix->ts.kind,
 			       &matrix->where);
   result->rank = 2;