Fix rare out-of-bounds write in FLACCL

[ledoge]

Fixes #315

Note that I have no prior experience with OpenCL and haven't tested this patch extensively, so I'm not fully confident that this doesn't break anything.

[c72578]

@ledoge Thanks for your PR.
Here is a build from GitHub Actions, which contains the updated flac.cl:
CUETools_2.2.6_2024-11-01_git_408b68d_Fix_rare_out-of-bounds_write_in_FLACCL.zip
SHA256: b245bffd489cc5f7a21132fc91edb78c8346333a969bd41b61d52bf8a5f22d67

@DarkVoyage, please check.

[DarkVoyage]

I use flac.cl a lot, so if I catch any glitches, I will write.
This version fixes the problem with that file.

[c72578]

@agressiv, would you mind testing the build above with e.g. NVIDIA GeForce RTX 4090 using FLACCL?

[agressiv]

Hi! I looked back through #315 and used the same settings, as well as re-encoding their sample file. I am not getting any errors:

D:\Burn>"C:\Program Files\CUETools_2.2.6\CUETools.FLACCL.cmd.exe" -11 --lax --fast-gpu "09 - Year Of The Cat.wav"
CUETools FLACCL 2.2.6, Copyright (C) 2010-2024 Grigory Chudov.
This is free software under the GNU GPLv3+ license; There is NO WARRANTY, to
the extent permitted by law. <http://www.gnu.org/licenses/> for details.
Filename : 09 - Year Of The Cat.wav
File Info : 96000 Hz; 6 channel; 24 bit; 00:06:39.2960000
Device : NVIDIA GeForce RTX 4090, Platform: "NVIDIA CUDA", Version: OpenCL 3.0 CUDA 12.7.33, Driver: 566.36
Results : 192.22x; 347923390 bytes in 00:00:02.0773098 seconds;

Sample file:

D:\Burn>"C:\Program Files\CUETools_2.2.6\CUETools.FLACCL.cmd.exe" -11 --lax --fast-gpu "clproblem.wav"
CUETools FLACCL 2.2.6, Copyright (C) 2010-2024 Grigory Chudov.
This is free software under the GNU GPLv3+ license; There is NO WARRANTY, to
the extent permitted by law. <http://www.gnu.org/licenses/> for details.
Filename : clproblem.wav
File Info : 44100 Hz; 2 channel; 16 bit; 00:18:36.7000000
Device : NVIDIA GeForce RTX 4090, Platform: "NVIDIA CUDA", Version: OpenCL 3.0 CUDA 12.7.33, Driver: 566.36
Results : 2745.81x; 210146 bytes in 00:00:00.4066926 seconds;

However, I used the previous 2.2.6 build (from 2024-06-28) and couldn't reproduce it there either. ¯\_(ツ)_/¯

[ledoge]

@agressiv The issue doesn't result in the encoder dying, but it does produce a broken file. Adding -o output.flac --verify to the arguments, or omitting --verify and then running flac -t output.flac, should show an error.

Also note: when you're testing different versions, to make sure that you're actually running the flac.cl file from the build you're testing and not a different cached one, you should update the timestamp on flac.cl by either changing something in the file and saving it or using something like the *nix touch command.

[agressiv]

I have the two different builds of 2.2.6 separated for testing. I still can't reproduce the error on the older june build.

D:\Burn>flac -s -d clproblem.flac -c | "C:\OldCUETools_2.2.6\CUETools.FLACCL.cmd.exe" - -11 --lax --fast-gpu --ignore-chunk-sizes --verify -o clproblem1.flac
CUETools FLACCL 2.2.6, Copyright (C) 2010-2024 Grigory Chudov.
This is free software under the GNU GPLv3+ license; There is NO WARRANTY, to
the extent permitted by law. <http://www.gnu.org/licenses/> for details.
Filename : -
File Info : 44100 Hz; 2 channel; 16 bit; 00:00:00
Device : NVIDIA GeForce RTX 4090, Platform: "NVIDIA CUDA", Version: OpenCL 3.0 CUDA 12.7.33, Driver: 566.36
Results : 1281.22x; 208126 bytes in 00:00:00.8715941 seconds;

D:\Burn>flac -t clproblem1.flac

flac 1.3.4
Copyright (C) 2000-2009 Josh Coalson, 2011-2016 Xiph.Org Foundation
flac comes with ABSOLUTELY NO WARRANTY. This is free software, and you are
welcome to redistribute it under certain conditions. Type flac' for details.`

clproblem1.flac: ok

[agressiv]

If I roll back to 2.25, I get this:

D:\Burn>flac -s -d clproblem.flac -c | "C:\CUETools_2.2.5\CUETools.FLACCL.cmd.exe" - -11 --lax --fast-gpu --ignore-chunk-sizes --verify -o clproblem2.flac
CUETools FLACCL 2.2.5, Copyright (C) 2010-2023 Grigory Chudov.
This is free software under the GNU GPLv3+ license; There is NO WARRANTY, to
the extent permitted by law. <http://www.gnu.org/licenses/> for details.
Filename  : -
File Info : 44100 Hz; 2 channel; 16 bit; 00:00:00
Device    : NVIDIA GeForce RTX 4090, Platform: "NVIDIA CUDA", Version: OpenCL 3.0 CUDA 12.7.33, Driver: 566.36
Progress  : 100%; 1362.29x; 00:00:00.7897904/00:00:00.7900000
Unhandled Exception: System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.
   at CUETools.Codecs.BitReader.read_rice_block(Int32 n, Int32 k, Int32* r)
   at CUETools.Codecs.Flake.AudioDecoder.decode_residual(BitReader bitreader, FlacFrame frame, Int32 ch)
   at CUETools.Codecs.Flake.AudioDecoder.decode_subframe_lpc(BitReader bitreader, FlacFrame frame, Int32 ch)
   at CUETools.Codecs.Flake.AudioDecoder.decode_subframes(BitReader bitreader, FlacFrame frame)
   at CUETools.Codecs.Flake.AudioDecoder.DecodeFrame(Byte[] buffer, Int32 pos, Int32 len)
   at CUETools.Codecs.FLACCL.AudioEncoder.process_result(FLACCLTask task)
   at CUETools.Codecs.FLACCL.AudioEncoder.do_output_frames(Int32 nFrames)
   at CUETools.Codecs.FLACCL.AudioEncoder.DoClose()
   at CUETools.Codecs.FLACCL.AudioEncoder.Close()
   at CUETools.FLACCL.cmd.Program.Main(String[] args)

I don't get this with any of my files, just clproblem.flac.

[agressiv]

And yes, if I remove --fast-gpu, 2.2.5 works just fine.

[c72578]

If I roll back to 2.25, I get this:

@agressiv thanks for the additional information concerning reproducibility of the issue using CUETools releases 2.2.6 and 2.2.5.

Concerning CUETools 2.2.5:
If you replace C:\CUETools_2.2.5\plugins\flac.cl with the updated flac.cl from the PR here, does it work then?

[agressiv]

If you replace C:\CUETools_2.2.5\plugins\flac.cl with the updated flac.cl from the PR here, does it work then?

No, it still gives the same unhandled exception.

If I copy CUETools.Codecs.FLACCL.dll from either build of 2.2.6, that gets rid of it, even if flac.cl is left alone at 2.2.5.