Commit 9f756bc67a84d4566bf74a0c2432aa55da404021
2023-04-04T13:53:21
Lossless decomp: Range-limit 12-bit samples 12-bit is the only data precision for which the range of the sample data type exceeds the valid sample range, so it is possible to craft a 12-bit lossless JPEG image that contains out-of-range 12-bit samples. Attempting to decompress such an image using color quantization or merged upsampling (NOTE: libjpeg-turbo cannot generate YCbCr or subsampled lossless JPEG images, but it can decompress them) caused segfaults or buffer overruns when those algorithms attempted to use the out-of-range sample values as array indices. This commit modifies the lossless decompressor so that it range-limits the output of the scaler when using 12-bit samples. Fixes #670 Fixes #672 Fixes #673 Fixes #674 Fixes #675 Fixes #676 Fixes #677 Fixes #678 Fixes #679 Fixes #681 Fixes #683