diff options
| author | Victor Stinner <victor.stinner@gmail.com> | 2012-05-07 13:02:44 +0200 |
|---|---|---|
| committer | Victor Stinner <victor.stinner@gmail.com> | 2012-05-07 13:02:44 +0200 |
| commit | 0576f9b4cf7e4b373eff1e610d6c63682a0ce089 (patch) | |
| tree | 11397888b29ab247c6d098be38df047bd48d2d4a | |
| parent | 202fdca133ce8f5b0c37cca1353070e0721c688d (diff) | |
| download | cpython-git-0576f9b4cf7e4b373eff1e610d6c63682a0ce089.tar.gz | |
Issue #14716: Change integer overflow check in unicode_writer_prepare()
to compute the limit at compile time instead of runtime. Patch writen by Serhiy
Storchaka.
| -rw-r--r-- | Objects/unicodeobject.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c index 0722312373..4bbaa35891 100644 --- a/Objects/unicodeobject.c +++ b/Objects/unicodeobject.c @@ -13242,8 +13242,10 @@ unicode_writer_prepare(unicode_writer_t *writer, newlen = writer->pos + length; if (newlen > PyUnicode_GET_LENGTH(writer->buffer)) { - /* overallocate 25% to limit the number of resize */ - if (newlen <= (PY_SSIZE_T_MAX - newlen / 4)) + /* Overallocate 25% to limit the number of resize. + Check for integer overflow: + (newlen + newlen / 4) <= PY_SSIZE_T_MAX */ + if (newlen <= (PY_SSIZE_T_MAX - PY_SSIZE_T_MAX / 5)) newlen += newlen / 4; if (maxchar > writer->maxchar) { |