CVE-2020-5313: Catch FLI buffer overrun · python-pillow/Pillow@a09acd0

@@ -40,8 +40,7 @@ ImagingFliDecode(Imaging im, ImagingCodecState state, UINT8* buf, Py_ssize_t byt return 0;
/* We don’t decode anything unless we have a full chunk in the input buffer (on the other hand, the Python part of the driver makes sure this is always the case) */ input buffer */
ptr = buf;
@@ -52,6 +51,10 @@ ImagingFliDecode(Imaging im, ImagingCodecState state, UINT8* buf, Py_ssize_t byt /* Make sure this is a frame chunk. The Python driver takes case of other chunk types. */
if (bytes < 8) { state->errcode = IMAGING_CODEC_OVERRUN; return -1; } if (I16(ptr+4) != 0xF1FA) { state->errcode = IMAGING_CODEC_UNKNOWN; return -1;