Merge pull request #20630 from WarrenWeckesser/f2py-possible-strcpy-buffer-overflow

BUG: f2py: Simplify creation of an exception message. Closes gh-19000.

1 files changed, 12 insertions, 16 deletions

diff --git a/numpy/f2py/src/fortranobject.c b/numpy/f2py/src/fortranobject.c
index 0b32137ef..c96378170 100644
--- a/numpy/f2py/src/fortranobject.c
+++ b/numpy/f2py/src/fortranobject.c
@@ -702,15 +702,14 @@ check_and_fix_dimensions(const PyArrayObject *arr, const int rank,
                          npy_intp *dims);
 
 static int
-count_negative_dimensions(const int rank, const npy_intp *dims)
+find_first_negative_dimension(const int rank, const npy_intp *dims)
 {
-    int i = 0, r = 0;
-    while (i < rank) {
-        if (dims[i] < 0)
-            ++r;
-        ++i;
+    for (int i = 0; i < rank; ++i) {
+        if (dims[i] < 0) {
+            return i;
+        }
     }
-    return r;
+    return -1;
 }
 
 #ifdef DEBUG_COPY_ND_ARRAY
@@ -795,15 +794,12 @@ array_from_pyobj(const int type_num, npy_intp *dims, const int rank,
         ((intent & F2PY_INTENT_CACHE) && (obj == Py_None)) ||
         ((intent & F2PY_OPTIONAL) && (obj == Py_None))) {
         /* intent(cache), optional, intent(hide) */
-        if (count_negative_dimensions(rank, dims) > 0) {
-            int i;
-            strcpy(mess,
-                   "failed to create intent(cache|hide)|optional array"
-                   "-- must have defined dimensions but got (");
-            for (i = 0; i < rank; ++i)
-                sprintf(mess + strlen(mess), "%" NPY_INTP_FMT ",", dims[i]);
-            strcat(mess, ")");
-            PyErr_SetString(PyExc_ValueError, mess);
+        int i = find_first_negative_dimension(rank, dims);
+        if (i >= 0) {
+            PyErr_Format(PyExc_ValueError,
+                         "failed to create intent(cache|hide)|optional array"
+                         " -- must have defined dimensions, but dims[%d] = %"
+                         NPY_INTP_FMT, i, dims[i]);
             return NULL;
         }
         arr = (PyArrayObject *)PyArray_New(&PyArray_Type, rank, dims, type_num,