qvm-convert-img: size constraint limitation: max_width=8192 max_height=5120

[h01ger]

Qubes OS version:

3.2

Affected component(s):

qvm-convert-img

Steps to reproduce the behavior:

$ wget https://upload.wikimedia.org/wikipedia/commons/4/4b/Long_Room_Interior%2C_Trinity_College_Dublin%2C_Ireland_-_Diliff.jpg
$ qvm-convert-img Long_Room_Interior%2C_Trinity_College_Dublin%2C_Ireland_-_Diliff.jpg test.jpg
trying Long_Room_Interior,_Trinity_College_Dublin,_Ireland_-_Diliff.jpg now
Traceback (most recent call last):
  File "/usr/lib/qubes/qimg-convert-client", line 51, in <module>
    main()
  File "/usr/lib/qubes/qimg-convert-client", line 45, in main
    img = qubesimgconverter.Image.get_through_dvm(args.src)
  File "/usr/lib/python2.7/dist-packages/qubes/imgconverter.py", line 207, in get_through_dvm
    return cls.get_from_stream(sys.stdin, **kwargs)
  File "/usr/lib/python2.7/dist-packages/qubes/imgconverter.py", line 144, in get_from_stream
    max_width=max_width, max_height=max_height))
ValueError: Image size constraint violation: width=9000 height=6796 max_width=8192 max_height=5120

Expected behavior:

images of any sizes are converted nicely. maybe not of any size, but max_width=8192 max_height=5120 are too limited constraints in 2018.

I'm not sure I fully understand why there has to be a limit at all, but if there has to be one I'd suggest to raise this to max_width=16384 max_height=10240 or maybe even max_width=32768 max_height=20480.

Actual behavior:

see above, it fails to convert.

Additional notes

I also didnt find where to change these values:

$ grep 8192 $(dpkg -L qubes-img-converter) 2>/dev/null
$

[DemiMarie]

Ran into this issue myself. I suspect it relates to some sort of ImageMagick config.

[DemiMarie]

Also, GitHub will complain when trying to use a trusted image as a profile picture. this was a bug with my tinyproxy config

[rapenne-s]

This is hardcoded in the image converter script

https://github.com/QubesOS/qubes-linux-utils/blob/master/imgconverter/qubesimgconverter/__init__.py#L38-L41

[alimirjamali]

We could (or perhaps should) add --allow-highres, --allow-press-print or a similar option to qvm-get-image to allow higher resolution images.

Medium format digital cameras could produce way beyond the current limit. Even some of the full-frames could surpass that limit. Let alone scanned images and digitally produced images for ImageSetter targets.

Photoshop limit is 30,000 x 30,000 pixels I did not find GIMP and Krita official limits. But Krita does not complain on 65000 x 65000 images.

This should be doable by passing max_width and max_height parameters to get_from_vm function and subsequently to get_from_stream function.

p.s. additional notes: GraphicsMagick has been used to process RGB images 64K by 64K pixels in size. I did not find specific limit for Numpy which is used for qubesimgconverter library.

[DemiMarie]

We could (or perhaps should) add --allow-highres, --allow-press-print or a similar option to qvm-get-image to allow higher resolution images.

I agree. The one limit I definitely think should be enforced is that the total size of the image in bytes should not be allowed to exceed INT_MAX, as this risks integer overflow or truncation vulnerabilities becoming exploitable.

[alimirjamali]

I agree. The one limit I definitely think should be enforced is that the total size of the image in bytes should not be allowed to exceed INT_MAX, as this risks integer overflow or truncation vulnerabilities becoming exploitable.

Good. I will work on it. I have been working on qubesimgconverter and qvm-get-image for a while and I know the mechanism fairly well.

[alimirjamali]

PR Submitted. Further notes:

With the default 1GB tmpfs, the actual limitation is the qubes.GetImageRGBA RPC service.

Even with 1GB tmpfs, a resolution of 16000x16000 pixels (~950MB) is easily achievable. That is barely over the current resolution of Phase One XF IQ4 150 Mega Pixel medium format camera. So I set the Highres limit to 16000x16000 in the patch.

I also added better error handling and clear messages to the patch.

[alimirjamali]

After discussing the issue with @andrewdavidwong on PR comments, we decided to break this issue to two independent issues:

1. Adding --allow-highres option to qvm-get-image to bypass the old max_width=8192 max_height=5120 soft-limit. The new soft-limit with --allow-highres is 64000x64000 pixels which is documented to be supported by GraphicsMagick (i.e. roughly 16GB of uncompressed image). The above PR should close this issue.
2. A new issue will be opened to make qubes.GetImageRGBA temp path configurable. That is to bypass the 1GB default /tmp size.

[alimirjamali]

Related: #5300