File Mode issue when using setuid bits

[mjmjelde]

Howdy,

I have created an application that requires the setuid bit to be on one of the executable. However, when I have a custom file_info mode set with the setuid bit set, it does not actually get properly set in the deb or rpm package that is created. In fact, some weird permissions appear for the file in the deb package and the rpm package is not even able to install.

This is what I have in my nfpm.yaml file:

contents:
  - src: dist/myexec
    dst: /usr/local/bin/myexec
    file_info:
      mode: 4555
      owner: root
      group: root

But this is what permission actually show up in the package:

root@0db5c89952b8:/# ls -la /usr/local/bin/myexec
-rwx--x-wx. 1 root root 50326500 Nov  4 16:01 /usr/local/bin/myexec

[erikgeiser]

You specified the file mode in decimal instead of octal which would be 04555. However, you still discovered a bug in the deb and apk packagers. The rpm packager does produce a file with suid bit when the mode is specified in octal, though.

The reason for the wrong behavior in the deb and apk packagers is that we use tar.FileInfoHeader which sets the mode to int64((*files.Content).Mode().Perm()) and the call to Perm() masks the suid bit with mode & ModePerm and ModePerm is 0777. We'll have to fix this by populating the tar header ourselves or by fixing the mode after calling tar.FileInfoHeader.

[erikgeiser]

See #395.