# HG changeset patch # Parent e0761e817deb20ccd8e6612f11ed79eb4caee3be Issue #nnnnn: Avoid zero-length memcpy() calls with null source pointers diff -r e0761e817deb Misc/NEWS --- a/Misc/NEWS Tue Jul 19 02:50:51 2016 +0000 +++ b/Misc/NEWS Tue Jul 19 02:56:44 2016 +0000 @@ -10,6 +10,9 @@ Core and Builtins ----------------- +- Issue #nnnnn: Avoid zero-length memcpy() etc calls with null source + pointers. + - Issue #27507: Add integer overflow check in bytearray.extend(). Patch by Xiang Zhang. diff -r e0761e817deb Modules/_ctypes/_ctypes.c --- a/Modules/_ctypes/_ctypes.c Tue Jul 19 02:50:51 2016 +0000 +++ b/Modules/_ctypes/_ctypes.c Tue Jul 19 02:56:44 2016 +0000 @@ -1381,8 +1381,10 @@ goto error; } stgdict->shape[0] = length; - memmove(&stgdict->shape[1], itemdict->shape, - sizeof(Py_ssize_t) * (stgdict->ndim - 1)); + if (stgdict->ndim > 1) { + memmove(&stgdict->shape[1], itemdict->shape, + sizeof(Py_ssize_t) * (stgdict->ndim - 1)); + } itemsize = itemdict->size; if (length * itemsize < 0) { diff -r e0761e817deb Modules/_ctypes/stgdict.c --- a/Modules/_ctypes/stgdict.c Tue Jul 19 02:50:51 2016 +0000 +++ b/Modules/_ctypes/stgdict.c Tue Jul 19 02:56:44 2016 +0000 @@ -391,9 +391,11 @@ } memset(stgdict->ffi_type_pointer.elements, 0, sizeof(ffi_type *) * (basedict->length + len + 1)); - memcpy(stgdict->ffi_type_pointer.elements, - basedict->ffi_type_pointer.elements, - sizeof(ffi_type *) * (basedict->length)); + if (basedict->length > 0) { + memcpy(stgdict->ffi_type_pointer.elements, + basedict->ffi_type_pointer.elements, + sizeof(ffi_type *) * (basedict->length)); + } ffi_ofs = basedict->length; } else { offset = 0; diff -r e0761e817deb Modules/hashtable.c --- a/Modules/hashtable.c Tue Jul 19 02:50:51 2016 +0000 +++ b/Modules/hashtable.c Tue Jul 19 02:56:44 2016 +0000 @@ -71,8 +71,10 @@ #define ENTRY_WRITE_PDATA(TABLE, ENTRY, DATA_SIZE, PDATA) \ do { \ assert((DATA_SIZE) == (TABLE)->data_size); \ - Py_MEMCPY((void *)_Py_HASHTABLE_ENTRY_PDATA((TABLE), (ENTRY)), \ - (PDATA), (DATA_SIZE)); \ + if ((DATA_SIZE) > 0) { \ + Py_MEMCPY((void *)_Py_HASHTABLE_ENTRY_PDATA((TABLE), (ENTRY)), \ + (PDATA), (DATA_SIZE)); \ + } \ } while (0) /* Forward declaration */ diff -r e0761e817deb Objects/listobject.c --- a/Objects/listobject.c Tue Jul 19 02:50:51 2016 +0000 +++ b/Objects/listobject.c Tue Jul 19 02:56:44 2016 +0000 @@ -648,7 +648,9 @@ goto Error; } } - memcpy(recycle, &item[ilow], s); + if (s > 0) { + memcpy(recycle, &item[ilow], s); + } if (d < 0) { /* Delete -d items */ Py_ssize_t tail;