py-imaging, py-pillow -- Buffer overflow in PCD decoder

The Pillow maintainers report:

In all versions of Pillow, dating back at least to the last PIL 1.1.7 release, PcdDecode.c has a buffer overflow error.

The state.buffer for PcdDecode.c is allocated based on a 3 bytes per pixel sizing, where PcdDecode.c wrote into the buffer assuming 4 bytes per pixel. This writes 768 bytes beyond the end of the buffer into other Python object storage. In some cases, this causes a segfault, in others an internal Python malloc error.

[source]