ImageMagick before 7.0.8-50 has an integer overflow vulnerability in the function TIFFSeekCustomStream in coders/tiff.c.
### Prerequisites

- [ y ] I have written a descriptive issue title
- [ y ] I have verified that I am using the latest version of ImageMagick
- [ y ] I have searched [open](https://github.com/ImageMagick/ImageMagick/issues) and [closed](https://github.com/ImageMagick/ImageMagick/issues?q=is%3Aissue+is%3Aclosed) issues to ensure it has not already been reported

### Description
<!-- A description of the bug or feature -->

There is a possible integer overflow vulnerability in TIFFSeekCustomStream in coder/tiff.c
```
case SEEK_CUR:
    {
      if ((profile->offset+offset) < 0)
        return(-1);
      profile->offset+=offset;
      break;
} 
```
https://github.com/ImageMagick/ImageMagick/blob/master/coders/tiff.c#L259

This issue is similar to the one which was fixed in https://github.com/ImageMagick/ImageMagick/commit/8b28a8708ca994c7c9f211d562a8109621cf4d15 and https://github.com/ImageMagick/ImageMagick/commit/114be1716d0a8a10df6f772ef558968a2ad9ab68.


Possible integer overflow in TIFFSeekCustomStream in coder/tiff.c
This is a GitHub Issue
repo:ImageMagick
owner:ImageMagick
Title : Possible integer overflow in TIFFSeekCustomStream in coder/tiff.c
Issue date:

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### Prerequisites

- [ y ] I have written a descriptive issue title
- [ y ] I have verified that I am using the latest version of ImageMagick
- [ y ] I have searched [open](https://github.com/ImageMagick/ImageMagick/issues) and [closed](https://github.com/ImageMagick/ImageMagick/issues?q=is%3Aissue+is%3Aclosed) issues to ensure it has not already been reported

### Description
<!-- A description of the bug or feature -->

There is a possible integer overflow vulnerability in TIFFSeekCustomStream in coder/tiff.c
```
case SEEK_CUR:
    {
      if ((profile->offset+offset) < 0)
        return(-1);
      profile->offset+=offset;
      break;
} 
```
https://github.com/ImageMagick/ImageMagick/blob/master/coders/tiff.c#L259

This issue is similar to the one which was fixed in https://github.com/ImageMagick/ImageMagick/commit/8b28a8708ca994c7c9f211d562a8109621cf4d15 and https://github.com/ImageMagick/ImageMagick/commit/114be1716d0a8a10df6f772ef558968a2ad9ab68.


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