Fix: SBO in CIccPcsXform::pushXYZConvert()

[ChrisCoxArt]

Fixes #625

Pull Request Checklist

• Have you followed the guidelines in Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same change?
• Have you built your Pull Request locally with the Build Instructions?
• Have you added or updated relevant tests?
• Have you added or updated relevant docs?

[xsscx]

Maintainer Review

2026-03-01 00:52:30 UTC

mkdir pr-632
cd pr-632
git clone https://github.com/InternationalColorConsortium/iccDEV.git
cd iccDEV
git fetch origin pull/632/head:pr-632
git checkout pr-632
cd Build
cmake -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_BUILD_TYPE=Debug -Wno-dev -DCMAKE_CXX_FLAGS="-g -fsanitize=address,undefined -fno-sanitize=leak -fno-omit-frame-pointer -Wall" -DENABLE_TOOLS=ON -DENABLE_STATIC_LIBS=ON -DENABLE_SHARED_LIBS=ON Cmake > cmake.log 2>&1
make -j32
wget https://github.com/xsscx/fuzz/raw/refs/heads/master/graphics/icc/hbo-CIccPcsXform-pushXYZConvert-IccCmm_cpp-Line3000.icc
wget https://github.com/xsscx/fuzz/raw/refs/heads/master/graphics/icc/hbo-CIccPcsXform-pushXYZConvert-IccCmm_cpp-Line3000-part2.icc
printf "'RGB '\nicEncodeFloat\n0.5\t0.5\t0.5\n" | Tools/IccApplyNamedCmm/iccApplyNamedCmm /dev/stdin 3 1 hbo-CIccPcsXform-pushXYZConvert-IccCmm_cpp-Line3000.icc 1 hbo-CIccPcsXform-pushXYZConvert-IccCmm_cpp-Line3000-part2.icc 1

Expected Output

Error 14 - Unable to begin profile application - Possibly invalid or incompatible profiles

[xsscx]

2026-03-01 00:56:10 UTC