From 86d81322c5c0ab67f89d64f56f6e77d4fe185910 Mon Sep 17 00:00:00 2001
From: Warren Weckesser <warren.weckesser@gmail.com>
Date: Tue, 29 Mar 2022 15:58:00 +0800
Subject: [PATCH] BUG: f2py: Simplify creation of an exception message. Closes
 gh-19000.

CVE: CVE-2021-41496

Upstream-Status: Backport [https://github.com/numpy/numpy/commit/271010f1037150e95017f803f4214b8861e528f2]

Signed-off-by: Mingli Yu <mingli.yu@windriver.com>
---
 numpy/f2py/src/fortranobject.c | 26 ++++++++++++--------------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/numpy/f2py/src/fortranobject.c b/numpy/f2py/src/fortranobject.c
index 3275f90..85c9c7f 100644
--- a/numpy/f2py/src/fortranobject.c
+++ b/numpy/f2py/src/fortranobject.c
@@ -637,14 +637,14 @@ static int check_and_fix_dimensions(const PyArrayObject* arr,
                                     npy_intp *dims);
 
 static int
-count_negative_dimensions(const int rank,
+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
@@ -721,14 +721,12 @@ PyArrayObject* array_from_pyobj(const int type_num,
         || ((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 *)
-- 
2.25.1