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Bug#767448: No way to override settings from /usr/share/initramfs-tools/conf-hooks.d/*

Cross-posted to 2 groups.

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> The UMASK variable is *documented* as affecting only the permissions
> for the initramfs image (which it doesn't seem to do reliably!) but it
> also affects the permissions for the files inside the initramfs.
 >
> When dropbear is used in the initramfs, the host private key must be
> kept secret and so the initramfs image must not be world-readable.  But
> most of the files installed in the initramfs can be world-readable.  Is
> that what you want to change?

No. I wasn't even aware that UMASK also affects the permission of files 
inside initramfs (as this is undocumented, as you said).

My setup is the following: Machine A with Debian boots from the network. 
Its /boot directory resides on machine B, which is simply a PXE server 
for machine A. /boot directory is mounted on machine A using sshfs. That 
way, on each update of machine A, kernel image and initramfs file are 
automatically transferred to machine B.

The problem is that tftpd on machine B has compiled-in limitation which 
allows only publicly readable files (o+r) to be served via TFTP.

Because dropbear package sets UMASK variable to 0077, (re)created 
initramfs file has no o+r permission. That means that it cannot be 
served by tftpd. So basically machine A won't boot on next reboot after 
update.

That's why I must override UMASK for (re)created initramfs.

Another solution for my problem would be to retain permission of 
existing initramfs file during initramfs regeneration and use UMASK only 
when initramfs file does not exist.

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Bug#767448: No way to override settings from /usr/share/initramfs-tools/conf-hooks.d/* Ben Hutchings <ben@decadent.org.uk> - 2015-12-11 03:50 +0100
  Bug#767448: No way to override settings from /usr/share/initramfs-tools/conf-hooks.d/* Ben Hutchings <ben@decadent.org.uk> - 2016-01-25 18:40 +0100
    Bug#767448: No way to override settings from /usr/share/initramfs-tools/conf-hooks.d/* Piotr Jurkiewicz <piotr.jerzy.jurkiewicz@gmail.com> - 2016-02-29 05:20 +0100
      Bug#767448: No way to override settings from /usr/share/initramfs-tools/conf-hooks.d/* Ben Hutchings <ben@decadent.org.uk> - 2016-04-17 03:00 +0200
        Processed: Re: No way to override settings from /usr/share/initramfs-tools/conf-hooks.d/* owner@bugs.debian.org (Debian Bug Tracking System) - 2016-04-17 03:00 +0200

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