Fix bug

[ 1346144 ] Segfaults from unaligned loads in floatobject.c

by using memcpy and not just blinding casting char* to double*.

Thanks to Rune Holm for the report.

diff --git a/Objects/floatobject.c b/Objects/floatobject.c
index d02e053c8d42b5817bf63939df2c52e37d43a194..b3f861f01444efce376debcfd8ed7bd248168eb9 100644 (file)
--- a/Objects/floatobject.c
+++ b/Objects/floatobject.c
@@ -1631,20 +1631,24 @@ _PyFloat_Unpack4(const unsigned char *p, int le)
                return x;
        }
        else {
+               float x;
+
                if ((float_format == ieee_little_endian_format && !le)
                    || (float_format == ieee_big_endian_format && le)) {
-                       char buf[8];
+                       char buf[4];
                        char *d = &buf[3];
                        int i;
 
                        for (i = 0; i < 4; i++) {
                                *d-- = *p++;
                        }
-                       return *(float*)&buf[0];
+                       memcpy(&x, buf, 4);
                }
                else {
-                       return *(float*)p;
+                       memcpy(&x, p, 4);
                }
+
+               return x;
        }               
 }
 
@@ -1722,6 +1726,8 @@ _PyFloat_Unpack8(const unsigned char *p, int le)
                return x;
        }
        else {
+               double x;
+
                if ((double_format == ieee_little_endian_format && !le)
                    || (double_format == ieee_big_endian_format && le)) {
                        char buf[8];
@@ -1731,10 +1737,12 @@ _PyFloat_Unpack8(const unsigned char *p, int le)
                        for (i = 0; i < 8; i++) {
                                *d-- = *p++;
                        }
-                       return *(double*)&buf[0];
+                       memcpy(&x, buf, 8);
                }
                else {
-                       return *(double*)p;
+                       memcpy(&x, p, 8);
                }
+
+               return x;
        }
 }